The Most Useful Site in the World

Every tool you need, already in your browser.

Popular:

/ search j/k move Enter open b toolbox t open it

1,424 private calculators, converters, simulators and labs across 35 categories — from mortgages and BMI to fire-ground maths and lucid dreaming. No install, no account, nothing you type leaves the page. Scroll the lists, or type to jump.

1424 free browser tools no ads no accounts no sign-ups

Seasonal 31 October

Halloween, sorted.

Sweets maths for the door, a stencil that carves cleanly, a costume that survives the weather and a route that ends before dark — 22 tools and a guide, all in the browser.

All 22 Halloween tools Read the Halloween guide

Throw the dial.

1,424 tools on one brass wheel. Flick it, catch it with your hand, let friction decide. Wherever the gold arm stops is where you land.

Drag to spin · double-click to flick · Space spins

Twelve openers from across the catalogue — age, BMI, mortgage, Wi-Fi QR, a tone generator. The ＋ saves one to your toolbox. Everything else is in the lists below.

A live popularity list — the same tools, ranked by how often people actually open them. A second way in if you would rather follow the crowd than the featured shelf.

35 categories · 1,424 tools

Finance, health, maths, STEM, survival, trucking, fire & rescue, lucid dreaming, dogs, birds, herbs, arcade, AI, astronomy — each tile is a full list of that field, not a marketing page.

The full list · 1424 tools

Every tool on one scrollable list. Type to jump, or ignore the box and just browse — featured, most-used and every category shelf stay above. / focuses the filter, j/k moves, Enter opens.

Full A–Z directory →
Sponsorship · one slot on this page Sponsors are always labelled, and a sponsor's own placement carries no tracking scripts, never takes more than 5% of the page and never changes what a tool does. Ask for the real traffic numbers before you buy. Sponsor this list →