The Most Useful Site in the World🏠 Top-level pages 15
🏠 Home
The main interactive catalogue — search, filter, view directory mode.
⭐ Most popular
60 hand-curated most-useful tools, organised by category.
🆕 Just added
The 10 newest tools added in the latest catalogue audit.
📚 Full index
The complete alphabetical-by-category index of all 1424 tools.
🎯 By use case
Find the right tool by describing the problem, not the name.
🔌 Embed
Every tool embeddable in one iframe. Copy the snippet and paste it anywhere.
ℹ️ About
Who built it, why, the principles behind the design.
📰 Press
One-paragraph factsheet, story angles, contact, and brand assets.
❓ Help & FAQ
20 most-asked questions, with honest answers.
📜 Changelog
Every change to the site, in order, with dates and tags.
☕ Donate
Support the project. The tools stay free either way.
🤝 Sponsor
Underwrite a specific tool or category for ongoing maintenance.
🎧 MrProphecy music
The companion product: UK hip-hop and animated soundscapes.
🎵 Music library
The full music catalogue, embedded player, and lyrics.
📖 Blog
Long-form, math-honest guides to the things the tools calculate.
🌍 Translated landings 12
🛠️ Every category (static fallback) 35
AI & Autonomous Agents (22)
Algorithms & Computer Science (79)
Anime & Otaku Culture (10)
Aquatics & Fishkeeping (10)
Astronomy & Space (36)
Birdwatching & Ornithology (10)
Cats & Feline Care (5)
Culinary & Food Science (33)
Dogs & Canine Care (10)
Field Investigation & Evidence (10)
Finance & Money (102)
Fire & Rescue Service (10)
Halloween (22)
Health & Fitness (48)
Home & DIY (52)
Horror & Paranormal (10)
Interactive Art & Living Worlds (51)
Legal & Professional (5)
Lucid Dreaming & Sleep (13)
Mathematics (84)
Mind-Blowing Demos (17)
Arcade (29)
Museum & Collection (29)
Music & Audio (40)
Natural Remedies & Herbs (10)
Productivity & Lifestyle (182)
Rocketry & Propulsion (10)
SaaS & Business Killers (72)
Science & Engineering (204)
Sports (56)
Survival & Emergency Readiness (13)
Trucking & Freight (10)
Virtual Worlds & Gaming (21)
Wellbeing & Community (36)
Writing & Language (73)
🔤 Every tool, A–Z (static fallback) 1424
🌐 10-Language Phrasebook
👁️ 20-20-20 Eye Rest Timer
🧭 3D Coordinate Converter — Cartesian, Cylindrical & Spherical
🔉 3D Cymatic Sound Sculpture
📐 3D Function Plotter
📐 3D Lines & Planes Calculator — Distance, Intersection & Angle
🧊 3D Shape Volume & Surface Area Calculator
🪐 3D Solar System Orrery
🌀 3D Spirograph Nebula
➗ 3D Vector Calculator — Dot, Cross & Triple Product Visualised
🔊 808 Sub-Bass Note Tuner & Harmonics Designer
🥃 ABV, Proof & Dilution
♿ Accessible Text Prep
🔐 Account Recovery Lockout Map
🌾 Acres ⇄ Hectares ⇄ m²
💆 Acupressure Point Relief Map
🌱 Adaptogen Synergy Matcher
🧠 ADHD Time & Task Lab
🧴 Adhesive Selector — Which Glue Sticks This to That?
🏠 Adulting Score Calculator
📜 Advanced History Timeline Builder
🏠 Advanced Household Chore Tracker
🧮 Advanced Number Theory Toolkit
🎨 Advanced Palette Swapper
📊 Advanced Percentages Explorer
🔳 Advanced QR Generator
🧠 Advanced RAG Playground — BM25 + Embeddings + Re-ranking
⏱️ Advanced Timer & Stopwatch
✨ Aesthetic Bio Generator
🎨 Aesthetic Color Palette Generator
🤖 AI Agent Orchestrator — Multi-Agent ReAct & Tool-Use
🔄 AI Agent ReAct Loop Studio
🧠 AI Chain-of-Thought Parser
📊 AI Context Window Budget Lab
🧮 AI Differential Equations Solver
⚡ AI Few-Shot Prompt Builder
🤖 AI Function Calling Validator
🔍 AI Hallucination & Fact Check
📚 AI Literature Analyzer
🔌 AI MCP Tool Protocol Inspector
🤖 AI Message Board
💰 AI Model Cost & Speed Matrix
🛡️ AI Prompt Injection Defense
⚡ AI Prompt Studio
🎭 AI Realistic Face Avatar — Procedural Canvas, FACS, Eye-Tracking, Lip-Sync
🧠 AI Reasoning Trace Visualizer — Chain-of-Thought & Self-Critique
🧠 AI Study Assistant
🌟 AI Super Realistic Face v4 — FACS Continuous Blending, Micro-Expressions 1/25s, 12 Visemes, GoT Eye-Tracking
🤖 AI Team Hub
🧠 AI Thinking Machine Lab — ToT, Reflexion, HyDE, RRF, Generative Memory (Research Stack 2022-2026)
🔧 AI Tool-Use Simulator — Function Calling & Byte 2.0 Integration
🤖 AI Toolbox Generator
📐 AI Vector Similarity Matrix
AI-Style Summary Generator
🌬️ Air Fryer ⇄ Oven Converter
🌫️ Airmass & Extinction Calculator
Algebra Solver
🧭 Alternative-Explanation Review
📆 Ambiguous Date Resolver — Is 03/04 March or April?
🔤 Anagram Solver
Anatomy Tools & Facts
🐫 Ancient Egypt Quiz
⏱️ Anime Binge Calculator
👑 Anime Character Archetypes
🎪 Anime Con Budget Planner
📜 Anime Filler Guide
🔮 Anime Mood Matcher
🎵 Anime Music BPM Analyzer
🎌 Anime Phrases & Tropes
🕒 Anime Schedule Converter
🧂 Anion Gap & Corrected Electrolytes
🕳️ Antipode & Gravity Tunnel Explorer
🔀 Apache & Nginx Redirect Generator
👶 APGAR Score Calculator
🔌 Appliance Running Cost Calculator
🏦 APR ⇄ APY Converter
🫧 Aquarium CO₂ Calculator
🌡️ Aquarium Heater & Chiller
💡 Aquarium PAR Lighting
🪨 Aquarium Substrate Estimator
🌊 Aquarium Volume & Weight
🎯 Archery Score Calculator
🧭 Argument Mapper
🫁 Arterial Blood Gas Interpreter
🔤 ASCII Banner Generator
📐 Aspect Ratio Resizer
🌀 Astronaut Artificial Gravity Calculator
📦 Astronaut Crew Consumables Planner
🪐 Astronaut Hohmann Transfer Planner
☢️ Astronaut Radiation Dose Ledger
🚀 Astronaut Rocket Equation & Delta-v Budget
Astronomy Calculators
🥇 Athletics Decathlon & Heptathlon Points
🎧 Audio File Size
🎚️ Audio Tone Generator
🌌 Aurora Solar Wind Chamber
🔍 Avian Anatomy & Field Marks
🗣️ Awkward Silence Filler
⚖️ Axle Weight & Bridge Formula Checker
✉️ B2B Cold Email Generator
🍼 Baby Formula Mixing
🍼 Baby Sleep & Feeding Day Planner
🎲 Backgammon
🌻 Backyard Bird Feeder Nutrition
🏸 Badminton Match Scorer
✉️ Bank Charge Dispute Letter Generator
📅 Bank Complaint Deadline Tracker
🔄 Bank Switching Bonus Calculator
⏲️ Bar ⇄ PSI ⇄ kPa
🏋️ Barbell Plate Loader & Warm-up Ramp
🏷️ Barcode & Label Studio
📊 Barcode Check Digit Validator
🌿 Barnsley Fern
🔐 Base64, Hex & Binary Text Encoder / Decoder
⚾ Baseball Stats Calculator
🐚 Bash Script Builder
🏀 Basketball Efficiency Calculator
🔗 Batch Link Cleaner
🔋 Battery Runtime (mAh)
Battery Sizing Calculator
🏗️ Beam Vibration Analyzer
🌬️ Beaufort Wind Scale
🕵️ Benford's Law First-Digit Scanner
🎰 Betting Odds & Each-Way Calculator
🦋 Bifurcation: Order to Chaos
📈 Big-O Complexity Explorer
🚴 Bike Gear, Cadence & Speed Calculator
🗓️ Bills & Paydays Cash-flow Forecaster
🔢 Binary, Bits & Bitwise Playground
🧠 Binaural Neuro Tuner
🔭 Binocular Optics & FOV Lab
🧮 Binomial Expansion Calculator — (a + b)ⁿ
Biology Tools
✨ Bioluminescent Luciferin Chemical Cascade Lab
🦠 Bioma Petri Dish
🪶 Bird Molt Cycle & Ageing Lab
🪺 Bird Nest Box Dimensions Guide
🎶 Bird Song Mnemonic Trainer
📋 Birding Life List & Big Year
Birthday Reminder
🕳️ Black Hole Horizon Calculator
💢 Blame Deflector 3000
🎧 Blind EVP Listening Worksheet
🩺 Blood Pressure Category Guide
⚕️ BMI Calculator
🔥 BMR & TDEE Calculator
🪵 Board-Foot Lumber Calculator
🧠 BODMAS Step-by-Step Trainer
🏋️ Body Fat Calculator
🧍 Body Surface Area Calculator
Boiling Point Finder
🧗 Bouldering Score Comparison
🏀 Bouncy Ball Box
🥊 Boxing 10-Point Must Scorecard
📊 Boxing Fight Outcome Projector
⚖️ Boxing Judging Criteria Weigher
🛎️ Boxing Knockdown & Count Rules Assistant
📈 Boxing Momentum & Swing Round Analyser
👊 Boxing Punch Stat Tracker
🔔 Boxing Round Timer & Bell
🔍 Boxing Scorecard Comparator
👨⚖️ Boxing Three-Judge Decision Simulator
⚖️ Boxing Weight Class & Weigh-In Checker
BPM Tap Counter (Pro)
🎀 Bra Size Converter
⚡ Brachistochrone & Tautochrone: The Curve of Fastest Descent
🔵 Braille Alphabet Trainer
✒️ Brand Mark Forge
⚡ Breaker Sizing Calculator
Break‑Even Calculator
🧱 Brick Calculator
👑 British Monarchs Quiz
🧠 Browser Vector Memory — IndexedDB + Semantic Search
🫧 Bubble Wrap Popper
🎲 Buffon's Needle π
Bulk Filename Previewer
🤝 Bulk-Buy Co-op Splitter: Halve Your Food Bills Together
🏷️ Business & Domain Name Generator
💳 Business Card Size Guide
📅 Business Days Calculator
🧩 Business Model Canvas
Business Writing Assistant
💾 Bytes ⇄ KB ⇄ MB ⇄ GB
🧳 Cabin Bag Size Checker
⚡ Cable Length & Voltage Drop
📈 CAGR — Compound Annual Growth
Calculus Helper
Calorie Calculator
📉 Calorie Deficit Timeline
🕯️ Candle Making Supplies Calculator
🍬 Candy & Sugar Stages Guide
🥩 Canine Daily Calorie Portioner
📊 Cap Table & Dilution
Capacitor Calculator
🎸 Capo Calculator
📱 Caption Generator
🚗 Car Care & MOT Due-Date Tracker
🚗 Car Ownership Cost Calculator (UK)
🤝 Care Handover Sheet
Career Path Planner
🫂 Carer's Respite Planner
🗺️ Cartographer's World Forge
🐱 Cat Age & Life-Stage Calculator
🐈 Cat Calorie & Portion Calculator
🧺 Cat Litter & Tray Planner
Cat Photo Viewer
🚨 Cat Poison & Household Hazard Checker
🍼 Cat Pregnancy & Kitten Timeline
🏹 Catapult Simulator
🔲 Cellular Automata Explorer
🌡️ Celsius ⇄ Fahrenheit ⇄ Kelvin
🌐 Censorship Monitor
❤️ CHA₂DS₂-VASc & HAS-BLED Calculator
🧭 Chaotic Magnetic Pendulum
✈️ Cheap Flight Fare Finder
🔴⚫ Checkers / Draughts
Chemistry Helper
♟️ Chess
♟️ Chess Elo Rating Calculator
🧪 Chi-Square Test Lab — Fit & Independence
Child Growth Tracker
🇨🇳 Chinese Tones & Pinyin
📐 Chladni Cymatics Plate
🔒 chmod Permission Calculator
🍫 Chocolate Tempering Curves
🎵 Chord Finder
🎼 Chord Progression Builder
🎄 Christmas Card Maker
🎵 Christmas Carol Karaoke Machine
🎄 Christmas Countdown
💰 Christmas Gift Budget Planner
🌿 ChronoGarden Terrarium
🎼 Circle of Fifths Explorer
🔌 Circuit Calculator
📚 Citation Generator
🔐 Classical Cipher Suite
🧹 Cleaning Schedule
💼 ClientFlow Pro — Quote, Invoice, Contract & E-Sign Studio
🧗 Climbing Anchor Force & Fall Factor Calculator
🚑 Clinical Fluid Requirements Calculator
📋 Clipboard History
🎬 Clip‑to‑Shorts Repackager
🕐 Clock Angle Calculator
🕰️ Clock Reading & Telling Time Trainer
👕 Clothing Size Converter
🎈 Coanda & Bernoulli Air Levitation
🧥 Coat, Hoodie, or Regret?
☕ Coffee Brew Ratio & TDS Lab
🔍 Cognitive Bias Detector
🔮 Coincidence Finder & Synchronicity Tracker
🍯 Cold & Flu Botanical Guide
🌊 Cold Water, Ice & Drowning Rescue
🌀 Collatz Conjecture Explorer
🎨 Color Converter & Palette Harmony Studio
🎨 Color Palette Extractor
✏️ Common English Mistakes Trainer
Community Apprenticeship Planner
🧊 Community Fridge Starter Kit: Feed Your Street
Community Project Budget Picker
Community Skills-to-Needs Matcher
Community Tool Library Scheduler
🚗 Commute Calculator
Compare Two Lists
🧭 Compass Bearings Trainer
🌈 Complex Function Landscape 3D
🧮 Complex Numbers Calculator
🌱 Compost Carbon:Nitrogen Balancer
💰 Compound Interest Calculator
🧱 Concrete Mix Calculator
⚡ Conduit Sizing Calculator
🔴⚫ Connect Four
🛰️ Consent Tech Watchlist
🤡 Conspiracy Theory Generator
⭐ Constellation Map
✨ Constellation Weaver
🛡️ Content-Security-Policy Builder & Checker
🔢 Continued Fraction Explorer — The Hidden Skeleton of Numbers
⚖️ Contract & NDA Builder
🛡️ Contract Sentinel Pro — Risk Analyzer
🧬 Conway's Game of Life
🍪 Cookie Consent Banner Builder
⏱️ Cooking Time Adjuster
🥄 Cooking Unit Converter
Cooperative Surplus Splitter
🧭 Coordinate Format Translator
📈 Coordinates Trainer
🎯 Corporate Meeting Bingo
🌐 CORS Header Builder
🗡️ Cosplay Prop Scaler
💵 Cost Per Mile & Break-Even Rate
🛒 Cost-Per-Use: Should You Buy It?
☎️ Could an AI Voice Clone Trick Your Family?
🏠 Council Tax Band Checker & Bill Estimator
⏳ Countdown to Any Date
🌍 Country Data Visualizer
🚩 Country Flags Quiz
💑 Couple Halloween Costume Ideas
🎛️ Coupled Oscillators Lab
✍️ Cover Letter Builder
📬 CPR Service & Response Deadline Calculator
✍️ Creative Writing Studio
📊 Credit Score Dispute Letter Generator
🏏 Cricket Net Run Rate Calculator
🏏 Cricket Run-Chase Calculator
🆘 Crisis Triage Guide
⏱️ Cron Schedule Builder
🖼️ Crop Factor & 35 mm Equivalent
🗂️ Cross-Platform Filename Safety Checker
🔐 Crypto & Hash Suite
🔷 Crystal Lattice & Unit Cell 3D
✨ CSS Animation Generator
🔘 CSS Border Radius Generator
🌑 CSS Box Shadow Generator
🎛️ CSS Filter Generator
↔️ CSS Flexbox Playground
🎨 CSS Glass & Gradients
🔲 CSS Grid Layout Generator
🎯 CSS Specificity Calculator
📊 CSV Data Studio
📊 CSV ⇄ JSON ⇄ Markdown Table Converter
〰️ Cubic Bézier Easing
✨ Curiosity Fact Deck
🖥️ cURL Command Builder
🥌 Curling Score Calculator
💱 Currency Converter
Curtain Width & Drop Calculator
🚴 Cycling Power & Speed Calculator
🔭 Daily Cosmic Awe & Micro-Wonder Portal
💧 Daily Hydration Calculator
🥩 Daily Protein Intake
✍️ Daily Writing — Streak & Word Goal
💧 Damp & Mould Diagnostic (UK homes)
⚡ Damped Oscillator Simulator
🌌 Dark Sky Quality Planner
🎯 Darts 501 Average & Leg Tracker
🎯 Darts Checkout Calculator
📅 Date Calculator
🌞 Daylight & Twilight Atlas
💰 Debt Payoff Calculator
⚖️ Decision Matrix Scorer
🎞️ Deck Forge
🪵 Deck Joist Span & Footing Calculator
🪵 Decking Calculator
⏱️ Deep Focus Timer
📸 Deep Sky Exposure Planner
🏛️ Deep Time Museum
📡 Deep-Space Communications Planner
🎛️ Delay Time BPM Calculator
🎲 Diceware Passphrase
💬 Difficult Conversation Scripter
📦 Dimensional Weight Calculator
📐 Dimensions of Reality
Discount Calculator
🧮 Discrete Math Toolkit
💾 Disk Space Analyzer & Planner
📈 Dividend Yield Calculator
🤸 Diving Score Calculator
🧬 DNA Helix 3D Builder
🧬 DNA → Protein Translator
🍫 Dog Chocolate Toxicity Calc
🎯 Dog Clicker Trainer & Sound
🏠 Dog Crate Sizing & Den Guide
🦮 Dog Daily Walk & Activity Calc
🥩 Dog Food Safety & Toxicity Key
🐕 Dog Human Years Age Clock
🐕 Dog Photo Viewer
📯 Dog Ultrasonic Whistle Lab
🩺 Dog Vital Signs & Hydration
🀄 Domino Chain Reaction
🁣 Dominoes
🔊 Doppler Effect Simulator
🌀 Double Pendulum Chaos
💡 Downlight Spacing Calculator
🌊 Drafting & Static Water Supply
🐦 Drinking Bird
🚗 Driving Emergency Survival Guide
🕐 Driving Hours & Duty Clock Planner
Drone Nearby? A Calm Safety & Reporting Guide
🧱 Drywall (Plasterboard) Calculator
🕰️ DST Meeting Drift Predictor
🧹 Duplicate Line Remover
🌙 Earth Tide Clock
⚡ Earthing Conductor Calculator
🫨 Earthquake Seismograph Lab
🌊 EchoPond Cymatics
🌍 Eco Footprint Calculator
🧪 eGFR & Creatinine Clearance Calculator
⏳ Einstein's Light Clock & Relativistic Time Dilation
⚡ Electric Field Lines 3D
⚡ Electrical Engineering Calculator
⚡ Electrical Load Calculator
📚 Electrical Standards Guide
🌊 Electromagnetic Wave & Polarization 3D
🛡️ Email Header Inspector
✉️ Email Subject Line Tester
📧 Email Template Generator
🌀 Emergence — Simple Rules, Infinite Complexity
📡 Emergency Communications & Radio Planner
👥 Employee True Cost Calculator
⚖️ Employment Tribunal Award Calculator
⚡ Energy Consumption Calculator
⚡ Energy Tariff Comparator
🛠️ Engine Displacement
🔄 Entropy & The Arrow of Time
🌡 Environmental Baseline Survey
🌍 Environmental Science Tools
📚 EPUB & eBook Builder
📐 Equation Solver
🧭 Equatorial Coordinate Finder
🧰 Equipment Reference-Check Log
⛰️ Erosion & Landscape Lab
📝 Essay Writing Assistant
💧 Essential Oil Dilution Calc
⚡ Euler's Identity: e^{iπ} = −1
🔌 EV Charging Cost & Time
🧑🚀 EVA Timeline & Consumables
🎒 Evacuation & Go-Bag Planner
📅 Event Reminder
🪑 Event Seating Planner
🔐 Evidence File Integrity Manifest
Evolution AI Walker
🧬 Evolution Arena — 3D Creature Evolution
🎙 EVP Audio Review Lab
🎂 Exact Age Calculator (Years, Months, Days)
🎯 Exam & Study Planner
📚 Exam Prep - Mathematics
🛡️ Excel CSV Corruption Guard
⚡ Exponents & Roots Calculator
📷 Exposure, Depth of Field & Filter Lab
✏️ Extruded 3D Text Studio
🔭 Eyepiece & Magnification Calculator
🏁 F1 Championship Points Calculator
🧵 Fabric Yardage Estimator
🔢 Factors & Multiples Trainer
💧 Faraday Fluid Waves
🪄 Favicon & SVG Icon Generator
📏 Feet & Inches ⇄ cm
🏗️ Fence Calculator
🧮 Fermi Estimator — Order-of-Magnitude Thinking
🧲 Ferrofluid Spiking Lab
✨ Fiber Optic Light Guide Lab
🐚 Fibonacci & Special Sequences
🌀 Fidget Spinner
🧪 Field Protocol & Control Planner
🔐 File Hash Checker
💰 Financial Budget Dashboard
⚖️ Financial Ombudsman Complaint Builder
🔥 Fire Escape & Smoke Safety Planner
🔥 FIRE Retirement Planner
🌡️ Firefighter Rehab & WBGT Heat Stress
🔥 Firefly Kuramoto Synchronization
🔥 Fireground Hydraulics — Friction Loss & Pump Pressure
📄 First Resume Builder
📊 Fiscal Quarter Finder
🍤 Fish Feeding & Vacation Planner
💊 Fish Medication Dosing
🐠 Fish Stocking Compatibility
🏃♂️ Fitness Score Analyzer
🌍 Flag & Capital Quiz
🔩 Flat-Pack Confidence Meter
✈️ Flight Delay Compensation Checker
🔥 Flue Draft & Stove Sizing Calculator
🌪️ Fluid Smoke Tunnel
🔠 Fluid Type Scale Generator
🫧 Foam Proportioning & Application Rate
🌫 Fog Machine Calculator
🍷 Food & Wine Pairing Matrix
📦 Food Parcel Stretcher: A Week of Meals From a Food Bank Box
🧊 Food Shelf-Life & Safety
🕸️ Food Web & Trophic Energy Lab
⚽ Football Points-Needed Calculator
🌍 Foucault Pendulum Spin
🎯 Foundation & Unit Circle
⚙️ Four-Bar Mechanism Lab
🌊 Fourier Series Synthesizer
🔢 Fractions Calculator & Visualizer
💼 Freelance Rate Calculator
🇫🇷 French Verbs & Pronunciation
⛽ Fuel Cost Calculator Pro
⛽ Fuel Economy Converter: MPG ⇄ L/100km ⇄ km/L
📐 Full Triangle Solver — Sine & Cosine Rules
⛰️ Function Terrain 3D Explorer
🌌 Galaxy Collision & Tidal Tails
🍺 Gallons, Litres & Pints
🔔 Galton Board & the Bell Curve
📊 Gantt & Timeline Studio
🌿 Garden Planning Assistant
🫁 Gas Leak & Carbon Monoxide Response
🧮 GCF, LCM & Prime Factors
✨ Generative Joy Kaleidoscope & Luminous Mandala
🧬 Genetics Laboratory
📐 Geodesic Area & Parcel Calculator
Geography Helper
Geology Tools & Facts
📏 Geometric Size Illusion Lab
Geometry Calculator
📐 Geometry Calculator
🇩🇪 German Cases & Gender
📡 Ghost Radar Video Prop
🎁 Gift Aid Calculator
Gift Helper 🎁
🙈 .gitignore Builder
🧠 Glasgow Coma Scale Calculator
🌤️ Go Outsideometer
Goal Tracker 🎯
⛳ Golf Stableford Points Calculator
⛳ Golf WHS Handicap Calculator
Grade Calculator 📊
🏔️ Grade, Climb & Descent Calculator
🕸️ Graph-of-Thought Lab — Aggregation, Transformation, GoT Reasoning (Besta 2023/2024)
🌌 Gratitude Constellation & Celestial Memory Map
🪨 Gravel & Aggregate Calculator
🕳️ Gravitational Lensing Lab
💬 Great Minds Quote Explorer
✈️ Great-Circle Route Planner
🌡️ Greenhouse Effect — Energy Balance Lab
🧭 Grid Reference Trainer (OS)
🕯️ Grief Companion
🛒 Grocery Budget Tracker
🪜 Ground Ladder Placement & Reach
🫁 Grounding & Breathing Coach
🧾 Group Expense Splitter & Settle Up
👯 Group Halloween Costume Planner
🧱 Grout & Tile Adhesive Calculator
🌾 Grow Your Calories
🎸 Guitar Fret Position Calculator
🤸 Gymnastics Score Calculator
🧭 Gyroscopic Precession Lab
📈 Habit Tracker
🍫 Halloween Candy Calculator
🎃 Halloween Costume Generator
🧥 Halloween Costume Weather Planner
🔌 Halloween Decoration Power Budget
🎨 Halloween Face Paint Planner
🍿 Halloween Movie Marathon Planner
🦇 Halloween Name Generator
🔦 Halloween Night Visibility Check
🎉 Halloween Party Games Planner
🎵 Halloween Party Playlist Planner
🔍 Halloween Scavenger Hunt Generator
🧠 Halloween Trivia Questions
🤾 Handball Scorekeeper
🧭 Hard Times Navigator: No Food, No Money — Start Here
✉️ Hardship Letter Writer: Ask for Breathing Space
🪐 HarmonicOrbit Loom
🔒 Hash Generator
🎩 Hat Size Converter
🌫 Haunted Atmosphere Generator
🎪 Haunted House Throughput Planner
📷 Haunted Photo FX Studio
🎬 Haunted Shoot Cue Sequencer
☣️ Hazmat Concentration Converter
🩸 HbA1c ⇄ Average Glucose
❤️ Heart Rate Zones Calculator
🥶 Heat & Cold Exposure Calculator
🥵 Heat Index Calculator
⛰️ Heightmap 3D Sculptor
⚠️ Herb & Prescription Safety
🩹 Herbal Poultice & Compress
🧴 Herbal Salve & Balm Crafter
🫖 Herbal Tea & Extraction Timer
🌿 Herbal Tincture Ratio Calc
🔢 Hex & Decimal Converter
💰 Hidden Bank Fee Calculator
🥾 Hike & Walk Time Planner
🎛️ Hip Hop EQ Frequency Masking & Pocket Allocator
🎙️ Hip Hop Vocal & Sidechain Compressor Calculator
📜 Historical Timeline Builder
🚗 HMRC Mileage Allowance
🌴 Holiday Entitlement & Pro-Rata Calculator
🌈 Holographic Laser Spectrograph
🏠 Home Inventory & Insurance Worksheet
🏠 Home Maintenance Planner & Service Log
🧾 Home Project Quote Comparator
🌅 Horizon & Line-of-Sight Calculator
🏎️ Horsepower, kW & Torque
💷 Hourly Wage, Overtime & Take-Home Estimator
💷 Hourly ⇄ Annual Salary
Household Chore Rota Generator
🚨 Household Emergency Plan
🪴 Houseplant Matchmaker
🌈 How Rainbows Form — Raindrop Ray Lab
📦 HTML / CSS Minifier
🔤 HTML Entity Encoder & Decoder
📋 HTML Table Generator
📝 HTML to Markdown Converter
📡 HTTP Status Code Encyclopedia
🗜️ Huffman Coding: How Compression Works
🫀 Human Anatomy Explorer
🌸 Hummingbird Nectar & Spoilage
🌀 Hurricane Engine
💧 Hydrant Flow Test & Water Supply
⚛️ Hydrogen Atom Orbitals 3D
🧊 Hypercube 4D Explorer
📷 Hyperfocal & Depth of Field
🏦 IBAN Validator & Formatter
🏒 Ice Hockey Goalie Stats
📅 ICS Event Builder
⚖️ Ideal Weight & BMI
🔢 IEEE-754 Converter
🎨 Image Colour Picker & Palette Extractor
🗜️ Image Optimiser Studio
🖼️ Image to Base64 Studio
🌀 Impossible Object Viewer
⚡ Inductance Calculator
📉 Inflation Impact Calculator
🏷️ Ingredient Label Allergen Decoder
🏡 Inheritance Tax & Probate Calculator
📷 Instant QR & Image Reader
🎶 Instrument Care Guide
🎸 Instrument Tuner Reference
🧊 Insulation Savings Calculator
⚛️ Interactive Periodic Table
⏳ Intermittent Fasting Window
🌍 International GPA Calculator
📈 Interpolation Lab — Between the Data Points
🎵 Interval Ear Trainer
⭐ Interview STAR Answer Builder
📦 Inventory Reorder Point Planner
⏱ Investigation Timeline Logger
📈 Investment Growth Calculator
👻 Invisible Character & Lookalike Detector
🧾 Invoice Late Fee Calculator
🧾 InvoiceForge Generator
⚖️ IR35 Inside vs Outside Comparator
🔁 Irregular Verbs Trainer
📚 ISBN-10 ⇄ ISBN-13 Converter
📆 ISO Week Number Finder
💧 IV Drip Rate & Infusion Calculator
🎃 Jack-o'-Lantern Carve Planner
🔢 Japanese Counters & Numbers
🎌 Japanese Kana Trainer
🎌 Japanese Kanji Helper
👑 Japanese Keigo Master
🧩 Japanese Particles Master
⚡ Japanese Verb Conjugator
✈️ Jet Lag Sleep Shift Planner
📖 JLPT Vocabulary Studio
💼 Job Offer Comparator
🪨 Joyful Zen Rock Garden & Ripple Raker
🎉 JoySpark: Micro-Victory Celebration Cannon
🔧 JSON & YAML Studio
🧩 JSON Flatten / Unflatten
🧬 JSON Schema Forge
🌌 Julian Day Converter
🔑 JWT Token Inspector
🗺️ Karnaugh Map Optimiser — Click the Cells, Get the Logic
☁️ Kelvin-Helmholtz Waves
⌨️ Keyboard Tester & Event Inspector
📊 Keyword Density & Word Frequency
⚪ Kinetic Momentum Cradle
🥄 Kitchen Converter & Baking Swaps
🧪 Kitchen Science Lab
🌀 Klein Bottle & Möbius Lab
🧶 Knitting & Crochet Yarn Studio
🪢 Knot Tying Guide — 18 Knots Worth Knowing
⛵ Knots ⇄ mph ⇄ km/h
🌦️ Köppen Climate Classifier
🇰🇷 Korean Hangul Trainer
💵 L$ Linden Dollar Converter
Lab Planner
Lab Safety Tools & Facts
🥬 Lacto-Fermentation Salt Calc
🪐 Lagrange Points & Gravity Well 3D
🪵 Laminate Flooring Calculator
Languages Tool
⏱️ Last-Minute Halloween Costume Finder
⏰ Late Payment Interest & Chaser Letter
📐 LaTeX Table & Maths Studio
🧺 Laundry Care & Stain Solver
Laundry Tracker
🫧 Lava Lamp
Lean Body Mass Calculator
📆 Leap Year & Weekday
🧭 Learning Style Self-Assessment
🌊 Learning to Swim in Not Knowing
🚗 Lease vs Buy Calculator
Leave-on-Time Planner
💡 LED Current-Limiting Resistor
💡 LED Watt Equivalent Calculator
♻️ Leftover Rescue Kitchen: Waste Nothing
🧲 Lenz's Law Eddy Current Tube
💡 Lighting Design Calculator
⚡ Lightning — Storm Anatomy in 5 Steps
⏳ Limitation & Claim Deadline Calculator (England & Wales)
💰 Linden Dollar Exchange
Linear Algebra Helper
📉 Linear Programming Lab — The Graphical Method
🧊 Linear Transformation 3D Visualizer
🔗 Link-in-Bio Page Builder
🐧 Linux Command Cheat Sheet
📡 Linux Process & Signal Reference
⚡ Lissajous Laser Projector
📅 Live Second Life Events
💬 LLM Prompt Token Counter
📼 Lo-Fi Vintage SP-1200 & Tape Saturation Lab
📊 Load Offer Decider & Counter-Offer
📈 Loan & Mortgage Amortization Schedule Calculator
Local Supplier Gap Finder
📋 Log Analyzer & Command Generator
📉 Logarithm Calculator
🕵️ Logic Detective Puzzle Club
⚡ Logic Gate Simulator
➗ Long Division Step-by-Step Trainer
Loop Seam Checker
📄 Lorem Ipsum & Placeholder Text
🌀 Lorentz Force 3D — Charged Particle in E & B Fields
🌪️ Lorenz Attractor — the Butterfly Effect
📜 LSL Script Generator
🏦 LTV Mortgage Calculator
🎧 Lucid Binaural REM Stimulator
🎯 Lucid Dream Quest Taskboard
📓 Lucid Dream Sign Analyzer
✨ Lucid Dream Stabilizer Lab
💊 Lucid Dream Supplement Clock
👁️ Lucid Reality Check Trainer
🎲 Ludo
LUFS Target & Headroom Planner
🔢 Luhn Check Digit Validator
💡 Lumens ⇄ Lux
🌙 Lunar Phase & Illumination
🌕 Lunar Tide Simulator
✨ Magic Background Eraser & Upscaler Pro
🔮 Magic Square Lab — Generate & Verify
🧲 Magnetic Field Log
✉️ Mailto Link Builder & Decoder
💰 Make Change Trainer (UK coins)
🪨 Mancala
🌀 Mandelbrot Set Explorer
📖 Manga to Anime Finder
🗺️ Map Projection Distortion Lab
🎱 Marble Run Builder
📊 Markdown & ASCII Table Generator
📄 Markdown Document Forge
📝 Markdown Live Editor
💹 Markup vs Margin Calculator
Materials Science Tools & Facts
Math Helper
🔁 Math Unit Converter
🌌 Math Universe Explorer
🧮 Maths Flashcards
Matrices Calculator
🛏️ Mattress Size Converter
Meal Cost Calculator
❤️ Mean Arterial Pressure
📈 Mean, Median & Mode
📊 Mean, Median, Mode & Range Trainer
📊 Mean, Median, Mode & Std Dev
🧂 Meat Brine & Cure Salinity
🌡️ Meat Internal Temperature Guide
Meeting Agenda Timebox Planner
💸 Meeting Cost Ticker
Meeting Planner & Scheduler
🔥 Melting Point Explorer
😂 Meme Generator — Your Image, Top & Bottom Text, No Watermark
🎭 Meme Translator
⏳ Memento Mori Life Ticker
🎯 Memorization Helper
🏛️ Memory Palace Builder
🧮 Mental-Math Sprint
⚡ Metabolic Age Estimator
🔮 Metamaterials & Negative Index Cloaking Device
☄️ Meteor Shower Sky Lab
🎙️ Mic, Speaker & Webcam Test — Pre-Meeting Device Check
🌱 Micro Garden: Grow Food With No Land
🔬 Microbiology Tools & Facts
🫸 Microgravity Push-Off Planner
🌤️ Migration & Thermal Lift Calc
🧠 MILD Lucid Dream Mantra Lab
📎 MIME Type Lookup
🧠 Mind Map Studio
📐 Miter & Bevel Angle Calculator
🧪 Mock Data Generator
🚀 Model Rocket Stability, CP & Ballast
〰️ Moiré Optical Interference
🔤 Mojibake Repair — Fix Garbled é ’ Text
⚛️ Molecule 3D Viewer
💸 Money Tracker
🎯 Monte Carlo π Estimator
🌘 Moon Phases & Eclipse Geometry
📡 Morse Code Translator
🏦 Mortgage Affordability — How Much Can You Borrow?
🏠 Mortgage Calculator
🏦 Mortgage Overpayment Calculator
🗺️ MostUsefulMaps — Distance & Place Finder
🚗 MOT, Road Tax & Insurance Deadline Reminder
⚡ Motor Startup Calculator
🏎️ Motorsport Lap Time & Stint Calculator
📊 Moving Average Forecaster — Smooth, Backtest, Step Forward
📦 Moving House Box & Supplies Estimator
🥁 MPC & SP Swing Groove Quantize Calculator
🧠 MrProphecy: Beat Memory
🏃 MrProphecy: Beat Runner
🤘 MrProphecy: Crowd Surf
🎛️ MrProphecy: Mix Board Challenge
🎧 MrProphecy: Name That Track
🥁 MrProphecy: Rhythm Tap
🛡️ MrProphecy: Studio Defender
🔤 MrProphecy: Title Scramble
🗺️ MrProphecy: Tour Manager
💿 MrProphecy: Vinyl Catch
🧬 MT4 / MT5 Genetic Copy-Trade Lab
🍂 Mulch Coverage Calculator
🚀 Multi-Stage Rocket Delta-v & Mass Budget Planner
🎤 Multi-Syllabic Rhyme & Cadence Flow Architect
🎵 Music Theory Visualizer
🎵 Music Transposer
Mutual Aid Shift Planner
🤝 Mutual Credit Ledger
👂 Mystery Hum & Whine Identifier
🪪 Nano ID Generator
📡 NATO Phonetic Alphabet Trainer
📡 NATO Phonetic Speller
⚡ Natural Electrolyte Tonic Lab
🍄 Nature ID Trainer
🕶️ ND Filter Exposure
🤝 Negotiation Prep Studio
🏐 Netball Scorekeeper
🧠 Neural Network Playground
🧠 NeuroSynapse Graph
🗣 Neutral Witness Statement Worksheet
📟 NEWS2 Early Warning Score
⚬ Nine Men's Morris
🔄 Nitrogen Cycle Tracker
🎹 Note Frequency Calculator
📅 Notice Period End Date
🔢 Number Base Converter
✍️ Number to Words (Cheque Writer)
🌊 Ocean Waves — The Secret Orbital Motion
📋 Offline Kanban Sprint Board
⚡ Ohm's Law Calculator
📏 On-Screen Ruler & Pixel-to-Physical Converter
🏋️ One-Rep Max Calculator
📝 Online Notepad — Autosave, Word Count & Download
🔬 Optical Tweezers & Trapping
🔬 Optics Calculator & Explorer
🛰️ Orbital Mechanics Lab
🚀 Orbital Mechanics Playground
🌸 Origami Fortune & Uplifting Destiny Weaver
📡 Oscilloscope Visualizer
⚫⚪ Othello (Reversi)
🔥 Oven Gas Mark Converter
📊 Overdraft & Interest Reclaim Calculator
🌙 Overnight Shift Duration
🌸 Ovulation & Fertile Window
⏱️ Pace Reading Timer
🕵️ Page Privacy Audit
🎨 Paint Calculator
🥘 Pan Size Converter
🧊 Pantry & Freezer Stock Tracker
📄 Paper Size Converter
Parcel Volumetric Weight Checker
🧠 Parts of Speech Trainer
Party Planner
📧 Passive Aggressive Email Translator
🛂 Passport Photo Size Guide
Password Generator
🛡️ Password Strength & Crack-Time Estimator
🗺️ Pathfinding Algorithm Visualizer
🛟 Payday Stretch: Make Your Last Pounds Last
⚡ PCB Trace Width Calculator
📄 PDF Copy-Paste Fixer
📄 PDF Toolkit Pro — Merge, Split, Compress & Extract
Peak Normalizer & WAV Export
🕰️ Pendulum Wave Array
🍲 Penny Meals: Survival Food Planner
🔷 Penrose Tiling Studio — The Aperiodic Decagon
📊 Percentage Calculator
📊 Percentage Change Calculator
🥚 Perfect Egg Timer
⚗️ Periodic Table Quiz
🧭 Permissioned Night-Shoot Planner
🔢 Permutations & Combinations
💰 Personal Finance Dashboard
🛡 Personal Safety & Awareness Planner
Pet Care Tracker
😈 Petty Revenge Idea Generator
🌸 Phenology & Growing Degree-Day Lab
📱 Phone Contract vs SIM-Only Calculator
📍 Photo Location Leak Scrubber
🖋️ Photo Watermark Studio
🌈 Photoelasticity & Birefringence: See Hidden Stress in Glass
🌿 Photosynthesis — Leaf Cross-Section Lab
🍄 Physarum Slime Mold & Mycelium Biocomputer Maze Solver
🔬 Physics Toolkit
🖼️ Picture Hanging Calculator
🐾 Pip: The Pocket Joy & Calming Companion
🔧 Pipe Sizing Guide
🎨 PixelVerse Canvas
🍕 Pizza Dough Ferment Master
🔍 Plagiarism Checker
📖 Plain Language Decoder
🕯 Planchette Story Prop
🪐 Planet & Ring Designer 3D
🌍 Planet Surface 3D Explorer
🌿 Plant Encyclopedia (Live)
🌱 Plant Spacing Calculator
🪣 Plastering Calculator
🌍 Plate Boundaries — Tectonics Lab
🔤 Platform Character Counter
🎵 Playlist Name Generator
☣️ Poison & Chemical Exposure Response
🚔 Police & Legal Speak, Decoded
💎 Polyhedra 3D Lab — Platonic, Duals & Truncations
🎲 Polyhedral Dice 3D Roller
🌀 Polynomial Roots Lab — Every Root, Real or Complex
⏱️ Pomodoro Flow Timer
🏊 Pool & Spa Volume
⚡ Power Calculator
🏋️ Powerlifting DOTS & Wilks Score
🎯 Practice Tracker
🧾 Pre-Trip Walkaround & DVIR Builder
🤰 Pregnancy Due Date & Week-by-Week Calculator
🤰 Pregnancy Weight Gain Guide
⚽ Premier League Live
💊 Prescription Prepayment (PPC) Checker — England
Presentation Word Budget Planner
⏱️ Price Tag in Hours of Your Life
🔍 Prime Factor Finder
🧮 Prime Factorisation Trainer
🖨️ Print Size & DPI Calculator
📄 Printable Paper Generator
🌈 Prism Optics & Snell's Law
🛡️ Privacy Policy Generator
🎙️ Pro Audio Studio — Record, Edit & Master in Browser
🎨 Pro Color Theme Studio — Palette, WCAG, Gradients & Export
🗄️ Pro Database Grid Studio — Airtable & Notion Killer
🎨 Pro Design Canvas Studio — Thumbnail, Poster & Social Maker
📄 Pro Doc Scanner Studio — OCR, PDF & Image to Text
✉️ Pro Email Visual Builder — BeeFree & Mailchimp Killer
🧠 Pro Flashcard Studio — Spaced Repetition (Anki Killer)
📝 Pro Form Builder Studio — Typeform & Google Forms Killer
🖼️ Pro Image Compressor Studio — Batch Resize, Convert & Optimize
🧾 Pro Invoice & Recurring Studio — Estimates, Invoices, Subscriptions
🧩 Pro JSON & API Workbench — Format, Query, Diff & Convert
🚀 Pro Landing Page Builder — Carrd & Webflow Killer
🔐 Pro Password Vault Studio — Generator, Encrypted Vault & TOTP
💷 Pro Rata Salary Calculator
🎬 Pro Video Toolkit — Trim, Compress, GIF, Thumbnail & Metadata
🧩 Pro Whiteboard Studio — Infinite Canvas, Sticky Notes & Drawing
🎲 Probability Calculator
🎲 Probability Paradox Lab
🌳 Probability Tree Builder — Branches, Marginals and the Bayes Flip
🕐 Procrastination Justifier
🚀 Productivity Score
📄 Professional CV Builder
🌍 Professional Ecology Calculator
🙃 Professional Excuse Generator
🎵 Professional Metronome
📅 Project Deadline Calculator
📊 Project Profitability Estimator
🎯 Projectile Motion Simulator
📽️ Projector Throw Distance
✍️ Proofreading & Style Checker
☁️ Psychrometric & Dew Point
🎤 Public Speaking Coach
🥧 Pumpkin Purée & Pie Planner
🎃 Pumpkin Stencil Generator
📝 Punctuation Mastery Guide
🐾 Puppy Adult Weight Forecaster
↔️ px ⇄ rem ⇄ em Converter
📐 Pythagoras Calculator
📱 QR Code Generator
❤️ QTc Interval (Bazett)
🧮 Quadratic Equation Solver
🔬 Quantum Energy Calculator
🔬 Quantum Eraser & Double Slit
⚛️ Quantum Superposition & Bloch Sphere Intuition Engine
☀️ Quantum Tunneling: Why the Sun Actually Shines
⚛️ Quantum Wave Tunneling
🔗 Query String Parser
🧠 Quick Quiz Maker
🧵 QuiltWeaver Tapestry
🏃 Race Pace Predictor & Training Paces
∠ Radians ⇄ Degrees Converter
☢️ Radioactive Decay Lab
🚆 Rail Delay Repay Calculator
⛰️ Rain Shadow & Orographic Lift Lab
🌧️ Rainfall & Flash Flood Lab
🌧️ Rainwater Harvest
🪣 Rainwater Harvesting & Tank Simulator
🎲 Random Number, Dice & Name Picker
👥 Random Team Generator & Group Splitter
🦅 Raptor & Flight Silhouette ID
➗ Ratio & Proportion
🗝️ Raycast Pocket Dungeon
⏲️ RC Time Constant
🔥 Re-entry Heating & Ballistic Coefficient Calculator
⚡ Reaction Time, Click Speed & Aim Test
📊 Readability Analyzer
📚 Reading Time Calculator
🍳 Recipe Converter
🧮 Recipe Ingredient Scaler
🎤 Recording Basics
🌳 Recursion & Memoization Explorer
🔴 Redshift & Cosmic Distance
📋 Redundancy & Notice Entitlement Calculator
⚡ Regex Studio — Tester, Explainer, Replace & Transform, Code and Command-Line Export
⏰ Reminder Tool
🏠 Rent Calculator
🏠 Rent vs Buy Calculator
🏠 Rental Move-in Condition Report
🏠 Rental Yield Deal Analyser
Repair Café Coordinator
🔧 Repair or Replace?
🚒 Required Fire Flow Calculator
✍️ Resignation Letter Generator
🎨 Resistor Color Code
🌟 Resolution & Limiting Magnitude
🍽️ Restaurant Bill Splitter with Itemised Shares
🎯 Resume ATS Scanner Pro — Beat the Bots
⏱️ Retainer Capacity Planner
💰 Retirement Calculator
Return Window Deadline Calculator
🌌 Reverb Pre-Delay & RT60 Decay BPM Calculator
💸 Reward Site Earnings Reality Check
🌊 Reynolds Number Simulator
📡 RF Link Budget & Fresnel Zone Planner
🪞 Rhyme Finder
🥁 Rhythm Generator
🍚 Rice-to-Water Ratio Calculator
🏷️ Rich Result Forge
🟦 Riemann Sum Lab — Area Under Any Curve
🧙 Riley: Goblin Smasher
💍 Ring Size Converter
🏞️ River Meander Lab
🔧 Roadside Breakdown Triage
🗺️ Robots.txt & Sitemap Generator
🪨 Rock & Mineral Identifier
🪨 Rock Cycle & Mineral ID Lab
🪂 Rocket Apogee & Ejection Delay Planner
📡 Rocket Ascent Flight Simulator — Gravity Turn & Max-Q
🛫 Rocket Launch Safety Check — TWR, Rail Speed & Wind
🔥 Rocket Nozzle & Thrust Calculator
🪂 Rocket Parachute Descent & Drift Calculator
⛽ Rocket Propellant Comparator — Isp, Density & Tank Size
📈 Rocket Thrust Curve Analyzer & Motor Class
📈 ROI Calculator
🔄 Romaji & Kana Converter
🏛️ Roman Numeral Converter
🏠 Roof Pitch & Rafter Calculator
🌡️ Room BTU & HVAC Sizing Calculator
🛋️ Room Layout Planner
🗺 Room Sweep Grid Mapper
🎯 Root-Finder Lab — Newton vs Bisection vs Secant
🪢 Rope Physics
📅 Round-Robin Fixture Generator
🔄 Rounding & Estimation Trainer
🚣 Rowing Erg Pace Calculator
🏉 Rugby Points Score Builder
⏳ Rule of 72 Doubling Time
📏 Rules of Thumb — 80 Shortcuts That Actually Work
🏃 Running Cadence & Stride Length
🏃 Running Split Pace Calculator
🛫 Runway & Burn Simulator
📉 SaaS Churn Revenue Impact
📈 SaaS LTV & CAC Calculator
💰 Salary Calculator
💼 Sales Commission Calculator
✂️ Sample Chop Slice & Bar Marker Calculator
Sample-Delay Alignment Calculator
🏜️ Sand Dune Lab
⏳ Sand Hourglass
⏳ Sandpile Mandala
🎅 Santa Tracker & Message Center
🎅 Santa's Naughty List Quiz
💰 Savings Calculator
🎯 Savings Goal & Emergency Fund Planner
Scale Drawing Converter
🌌 Scale of Reality
🎹 Scale Trainer
🛡️ Scam Sense Checker
🫁 SCBA Air Management & Turnaround Pressure
🇪🇺 Schengen 90/180 Calculator
🔥 Schlieren Optics Airflow
🔬 Science Experiment Generator
Science Quiz Generator
🔬 Science Study List
🔬 Scientific & Everyday Unit Converter
🧮 Scientific Calculator
📚 Scientific Formula Library
🔬 Scientific Method Helper
🔬 Scientific Notation & Sig Figs
🔤 Scrabble Score Calculator
🎥 Screen & Camera Recorder Studio
🖥️ Screen PPI Calculator
🔩 Screw & Drill Bit Size Chart
🍓 Seasonal Produce Calendar — What to Buy This Month
🌗 Seasons & Earth's Tilt — 3D Explainer
🌊 Seawater Salinity & Density
🏗️ Second Life Builder's Mate
🛒 Second Life Marketplace Search
🗺️ Second Life Region Map
📚 Second Life Surnames Encyclopedia
🖼️ Second Life Texture Tool
💌 Secret Kindness Mission & Joy Ripple Engine
🎁 Secret Santa Generator
🛡️ Section 75 Claim Calculator & Letter
🔒 Secure Vault — Text & File Encryption
📖 See Your Life Through a Narrator's Eyes
🌱 Seed Germination Calculator
📦 SemVer Compare & Bump
🔐 Sensitive Data Redactor
🔍 SEO Studio — Page Audit, Keywords & Readability, Search and Social Previews, Meta Tag Generator
🔢 Sequences & Series Calculator
🎼 Sheet Music Reference Generator
📏 Shelf Bracket Calculator
🗓️ Shift Labour Cost Planner
👟 Shoe Size Converter
🔷 Shoelace Polygon Area Calculator
🐎 Showjumping Faults Calculator
📧 Signature Forge
✒️ Signature Pad — Draw or Type, Save as PNG or SVG
⚖️ Simultaneous Equations Solver — Every Line of Working
🤝 Sincere Apology Builder
🗑️ Skip Hire Volume Calculator
📏 SL Avatar Height & Proportion Calculator
👥 SL Group Slot Calculator
🏠 SL Land Tier Calculator
🔺 SL Mesh Upload Cost Calculator
👗 SL Outfit Planner
🧱 SL Prim Budget Planner
🌀 SL Teleport & SLURL Planner
🖼️ SL Texture Upload Cost Calculator
🕐 SL Time Converter
🛏️ Sleep Cycle Calculator
😴 Sleep Debt Calculator
🛡️ Sleep Paralysis Navigator
Slinky Physics
🦴 SLS-Style Figure Composer
🔗 Slug Generator
⚖️ Small Claims Court Guide & Cost Calculator
📄 Small Claims Letter Before Action Builder
📚 Smart Flashcards
Smart Garden Task Planner
🌐 Smart Graphing Calculator
💰 Smart Loan Calculator
🥗 Smart Macros Calculator
🧳 Smart Packing List
🎯 Smart Quiz Generator
🛒 Smart Shopping List
🔍 Smart Spelling Checker
🚭 Smoking Cost & Quit Savings Planner
🐍 Snakes & Ladders
🎱 Snooker Snookers-Required Calculator
❄️ Snowflake Crystal Lab
🎨 Social Image Resizer
🖼️ Social Preview Generator
🏛️ Socratic Thinking Coach
🌱 Soil & pH Guide
⚡ Solar Inverter Sizing
☀️ Solar Panel Calculator
🪐 Solar System Explorer
🌌 Solar System Simulator
🪐 Solar System Size Comparator
🎐 Solarpunk Wind Chime Sanctuary
Solidarity Fund Runway
🏺 Solids of Revolution Volume Calculator 3D
🌊 Soliton Wave Flume Tank
🧪 Solution Dilution Lab
🎵 Song Writer (General Advice)
📊 Sorting Algorithm Visualizer
🔊 Sound Decibel Calculator
🍞 Sourdough Baker's Math Lab
🥩 Sous Vide Time & Temperature
🫧 Spacecraft Cabin Atmosphere Planner
🔋 Spacecraft Power & Eclipse Budget
🕳️ Spacetime Curvature
🇪🇸 Spanish Verb Conjugator
🔊 Speaker Ohm Wiring
🚀 Special Relativity Simulator
🚗 Speed Distance Time Calculator
⚡ Speed Reading Trainer
⚡ Speed-Reading RSVP Trainer
📬 SPF & DMARC Record Builder and Checker
⚪ Sphere, Cylinder & Cone Volume
🌶️ Spice Blend Scaler — Homemade Mix Recipes
🎡 Spin the Wheel — Random Name & Decision Picker
📻 Spirit Box Wordstream Studio
🧪 Split Test Lab
📖 Spooky Story Skeleton Generator
🎮 Sprite Sheet Studio
🗃️ SQL Formatter & Query Helper
🎬 SRT Subtitle Time Shifter
🔑 SSH Command Generator
🪜 Stair Stringer Calculator
🚀 Starfield Warp Drive
🐦 Starling Murmuration
🧊 States of Matter — Particle Simulator (H₂O)
📊 Statistics Calculator
⚙️ Steam Tables Lab
🚶 Steps to Calories Converter
Stereo & Mono Compatibility Analyzer
📻 Stochastic Resonance: Reveal Hidden Signals With Noise
⚖️ Stone, Pounds ⇄ kg
🛑 Stopping Distance & Following Gap
⏱️ Stopwatch & Precision Timer
🎲 Story Dice Plot Twister
🏘️ Street Sharing Planner
💳 Stripe & PayPal Fee Calculator
📝 Structured Investigation Report Builder
🧱 Stud & Wall Framing Calculator
📚 Study Planner
📚 Study Timer (Pomodoro)
🔍 Subject Access Request (SAR) Generator
🌐 Subnet & CIDR Calculator
Subscription Tracker
🎬 Subtitle Drift Fixer — Two-Point Sync
🧩 Sudoku Trainer (unique puzzles, hints & solver)
🍖 Sunday Roast Dinner Timeline
🌞 Sundial Designer
🧲 Superconductor Flux Pinning
🌿 Surds Simplifier — Pull the Squares Out
🏔️ Surface Curvature 3D — Gaussian Curvature, Gradient & Critical Points
Surplus Materials Exchange
⚡ SVG Path Optimizer & Minifier
📐 SVG Path Visualizer
🏊 Swimming Pace & CSS Calculator
🔤 Syllable Counter
🔄 Synonym Finder
⚙️ Systemd Service Generator
🔥 Tabata Timer
🏓 Table Tennis Scorer
🗣️ Talk to Your Body (It's Been Trying to Tell You Something)
🚚 Tanker Shuttle Delivery Rate
🔩 Tap Drill Size
📋 Task Prioritizer Matrix
💰 Tax Estimator & Calculator
🍵 Tea Brew Temperature & Steep Guide
🌋 Tectonic Plate Drift Calculator
🔭 Telescope Collimation Check
🎵 Tempo & BPM Map
🎳 Ten-Pin Bowling Score Calculator
🏠 Tenancy Deposit Calculator (England)
🎾 Tennis Match Scorer
⚖️ Terms of Service Generator
⚡ Tesla Atmospheric Plasma
🌟 Testimonial Card Generator
🔡 Text Case Converter
🔎 Text Diff Checker
📊 Text Statistics Analyzer
✍️ Text to Handwriting
🖼️ Text to Image Generator
🔤 Text ⇄ Hex ⇄ Binary
🔊 Text-to-Speech Reader (Offline Browser Voices)
🌙 The 3am Worry Sorter
🧠 The Bayes Workshop
🛡️ The Blazon Workshop
🪙 The Coin Room
📐 The Constant Treasury
🔢 The Constants of Reality
🌀 The Coriolis Effect — Turntable & Storms
☀️ The Daylight Lab
📚 The Dewey Stacks
🔊 The Echo Chamber
⚗️ The Element Hall
🧬 The Emotions You Inherited (But Never Chose)
🕯️ The Grief No One Validates
🥈 The Hallmark Bench
🧬 The Hominin Corridor
🐍 The Identities You're Dragging Behind You
🎭 The Illusion Gallery
📜 The Kalends Desk
😄 The Laugh Laboratory & Mood Prescription
💡 The Light Budget
🌌 The Messier Gallery
💎 The Mohs Gallery
🧪 The Moisture Lab
🏯 The Nengō Desk
👁️ The Observer Effect
🏛️ The Orders Bench
🧮 The Overthinker's Calculator
🎨 The Pigment Cabinet
💧 The Pipe Lab
⚛️ The Quantum World
👑 The Regnal Desk
🦕 The Scale Hall
🏺 The Seven Wonders
🏗️ The Stress Gallery
🧱 The Thermal Wall
🏷️ The Thing Namer
🏷️ The Tombstone Desk
⚡ The Watt Exchange
🔥 Thermodynamics Calculator
🧵 Thread Splitter for Long Posts
🎮 Tic Tac Toe Game
🌊 Tidal Window & Crossing Planner
🧱 Tile & Flooring Estimator
⏱️ Time Calculator — Add, Subtract & Convert Hours and Minutes
⏱️ Time Tracker & Timesheet Studio
🌍 Time Zone Converter
⏱️ Timelapse Interval
⏳ Timeline of Everything
🔢 Times Tables Drill Trainer
🔉 Tinnitus & Hearing Relief Studio
✊ Tiny Revolts Against Your Own Prison
💸 Tip & Split Calculator
✅ To-Do List — Simple, Offline, Remembers Itself
🎤 Tongue Twister Trainer
🌪️ Tornado & EF-Scale Lab
⚡ Torsional Vibration Lab
🏆 Tournament Bracket Generator
🗼 Towers of Hanoi
🛸 TR-3B Flight Simulator
📦 Trailer Load & Pallet Planner
🎙️ Transcribe & Subtitle Studio Pro
⚡ Transformer Sizing Calculator
🌍 Translation Helper
⚡ Trap & Drill Hi-Hat Roll Pattern Generator
✈️ Travel Trip Planner
🏊♂️ Triathlon Race Planner
🍬 Trick-or-Treat Route Planner
🛞 Truck Tyre Load, Pressure & Temperature Check
🌀 True Scale of Space
🧮 Truth Table Generator
🌊 Tsunami Runup Simulator
🐆 Turing Reaction Diffusion
🦃 Turkey Thaw & Cook Time
📺 TV Viewing Distance Calculator
⌨️ Typing Speed Test
⌨️ Typing Story Sprint
🛞 Tyre Size Comparison
🎓 UCAS Tariff Points
🍺 UK Alcohol Units Calculator
🧒 UK Childcare Cost Calculator
🗺️ UK Counties & Regions Quiz
🏛️ UK Court, Tribunal & Probate Fee Calculator
🅿️ UK Parking Appeal Builder
📮 UK Postcode Formatter
🏠 UK Stamp Duty Land Tax Calculator
🚚 Ultimate Moving Planner
🎵 Ultimate Music Quiz
🔊 Ultrasonic Acoustic Levitation
🐬 Underwater Acoustics Lab
🌐 Unicode Converter
🛒 Unit Price Comparator
🖼️ Universal Thumbnail Generator
🔄 Universal Unit Matrix
🌌 Universe Mysteries — Geometry Lab
⏱️ Unix Timestamp Converter
🔗 URL Encoder, Decoder & Parser
🕵️ User Agent & Browser Client Inspector
🎮 Username Generator
🔗 UTM Campaign URL Builder
🆔 UUID / GUID & Random ID Bulk Generator
⚡ Van de Graaff Generator
💷 VAT / GST / Sales Tax Calculator
🪪 vCard Generator
🌀 Vector Field, Divergence & Curl 3D
🔵 Venn Diagram Visualiser
🛡️ Vibration Isolator Designer
🎬 Video Bitrate File Size
🎚️ Vinyl Sample Pitch & Semitone BPM Shifter
🔨 Virtual Builder's Workmate
🌐 Visit Supadupaman Sapphire in Second Life
🏃 VO₂ Max Calculator
Vocabulary Trainer
🌋 Volcano Eruption Simulator
🏐 Volleyball Score Sheet & Rotation
⚡ Voltage Divider
⚡ Voltage Drop Calculator
🗿 VoxelMonolith 3D
📏 Waist-to-Height Ratio
📏 Waist-to-Hip Ratio Calculator
🔩 Wall Anchor Selector
🧻 Wallpaper Estimator
🧪 Water Change & Salinity
💧 Water Cycle Simulator
💧 Water Density Anomaly Lab
⚡ Water Dielectric Lab
🚰 Water Hardness (LSI) Lab
🧪 Water Ionization & pH Lab
🏔️ Water Phase Diagram Lab
💧 Water Purification Planner
🧪 Water Surface Tension Lab
〰️ Wave Machine
🌙 WBTB Lucid Dream REM Planner
👁️ WCAG Contrast & Vision
⛽ Web3 Gas Fee Estimator
💒 Wedding Budget Planner
Weekly Meal Planner
💉 Weight-Based Dose & Volume Calculator
🏋️ Weightlifting Sinclair Score
🤔 What Does That Emoji *Actually* Mean?
🧠 What Is Consciousness?
🎬 What Should I Watch?
🛞 Wheelbuilding Spoke Length & Tension Calculator
When Everyday Services Go Down: A Readiness Map
Which Year Are You? 🕰️
🌧️ White, Pink & Brown Noise — Sleep & Focus Sound Machine
🏷️ Wholesale Pricing & Margin
🌞 Why Is The Sky Blue? — Rayleigh Scattering Lab
🕳️ Why Is There Something Rather Than Nothing?
📶 Wi-Fi QR Pass Generator
📶 WiFi Speed & Download Time Calculator
🌀 WILD Hypnagogia Transition
🔥 Wildfire Behaviour Lab
Will AI Take My Job? — Task Exposure Simulator
🛋️ Will It Fit? Sofa & Furniture Path Checker
☕ Will You Sleep Tonight? (Caffeine Check)
🌫️ Wilson Cloud Chamber
🌬️ Wind Chill Calculator
✈️ Wind Triangle & Flight Leg Planner
🌬️ Wind, Fetch & Wave Forecaster
⚡ Wire Gauge Calculator
☁️ Word Cloud Generator
⏱️ Work Hours & Pay Calculator
🌍 World Capitals Quiz
🌐 World Clock & Time Zone Board
🗺️ World Map Geography Trainer
🌍 World Meeting Time Zone Planner
✍️ XMAS Card Writer Assistant
📐 XML Formatter & Validator
🎲 Yahtzee
🍞 Yeast Converter
📖 You're Already Living Your Dream (You Just Forgot)
🛡️ Your Inner Critic Is Trying to Save You
⏰ Your Life Is Telling a Different Story Than You Think
👧 Youth Team Rotation Planner
🎛️ YouTube DJ Mixer
💼 Zero-Capital Income Starter
φ Golden Ratio Crop Calculator
ᚠ The Rune Cabinet
𓂀 The Uniliteral Case
🤖 Machine-readable 17
sitemap.xml
The full XML sitemap for search engines.
feed.xml
RSS 2.0 feed of changes and new tools.
llms.txt
Machine-readable overview for LLM crawlers.
llms-full.txt
The same overview with every tool listed in full.
.well-known/ai.txt
AI policy: training, retrieval, republishing rules.
.well-known/mcp.json
MCP server manifest for agent clients.
.well-known/security.txt
Security disclosure address and expiry.
robots.txt
Crawler rules (explicit allow for major AI crawlers).
cards/cards.json
Complete tool catalogue as JSON.
cards/cards-lite.json
Name/title/category only — the fast tier the home page boots from.
tools-index.json
Catalogue with categories and tags, for directories.
api/tools.json
The same index under the /api/ path agents are told to use.
related.json
Computed related-tools map, one entry per tool.
jobs.json
Multi-step jobs: each step, its carried values and where they go.
intents.json
Plain-language routes the home page's solve box recognises, and the tool each opens.
manifest.json
PWA manifest.
manifest.tools.json
Tool shortcuts for the installed PWA.