Target: producthunt.com When: Tuesday or Wednesday, 00:01 PT (the launch window reset) Page: https://www.producthunt.com/posts/new (or the maker dashboard)
Primary: 562 free browser tools. No accounts, no display ads. Open source.
Alternates:
562 free browser tools. No accounts, no display ads. Open source.562 free, private, browser-side tools. Open source.The most useful site in the world. 562 tools. Free.A non-commercial catalogue of 562 free, browser-side tools. Mortgage calculator, BMI, compound interest, password generator, BPM tapper, JSON formatter, colour contrast checker, invoice generator, and 550+ more. No accounts, no display ads. Open source. One person, built in two years, in Luton, UK.
The Most Useful Site in the World is a non-commercial project I've been building for two years.
The whole site is 562 free, browser-side tools. Every one of them runs in your browser, with no account, no email, no display ads, no upsell.
The catalogue includes:
- Finance: mortgage, compound interest, debt payoff, salary, lease vs buy, stamp duty, affordability, investment, unit-price comparator, credit card
- Health: BMI, BMR, calorie, heart-rate, sleep cycle, period tracker, water intake
- Maths: percentage, fractions, scientific, statistics, geometry, conversions
- Music & audio: BPM tapper, metronome, tuner, chord builder, scale visualizer
- Writing & language: word counter, grammar checker, paraphraser, JSON formatter, regex tester, password generator
- Image & design: colour palette extractor, WCAG contrast checker, image format converter, SVG-to-PNG
- Astronomy: eyepiece calculator, lunar phase, star chart, telescope collimation
- And 500+ more
The thing I am most proud of: the no-display-ads part. View source on any page. You will not find an ad slot, an ad network script, a sponsored-content block, or a retargeting pixel. The whole markup is the tool and its text. (I do run Google Analytics for measurement — that’s how I know which guides convert — but Analytics does not place ads.)
The thing I am least proud of: the homepage. I have been told it's “a wall of 562 emoji”. It is. I am working on it.
Built by: one person (me, Russell), in Luton, UK, in the evenings and weekends. Stack: vanilla JavaScript, one HTML file per tool, no framework, no build step, no npm. Open source: https://github.com/mrpr0phecy/mrpr0phecy Cost to run: £8/month for a server in my house. Revenue model: none. The donate link has made £34.50 in 9 months.
Happy to answer any questions. 🛠️
Open SourceProductivityPrivacyJust me. Single maker launch.
T-minus 1 hour (before launch):
T-zero (00:01 PT):
T+30 minutes:
T+2 hours:
T+24 hours:
INCOME.mdAuthor here. A few things I should have put in the main post:
- The site is non-commercial. There is no business model. There is no display ad inventory, no email list, no newsletter, no upsell, no pop-up. The donate link has been live for 9 months; total donations received: £34.50. (The third-party scripts on the site are Google Analytics, for measurement, and three.js / cannon.js / the YouTube IFrame API on the specific tool pages that need them. None are advertising.)
- The number 562 is honest. There are 562 separate tool pages and a
cards.jsonfile with all 562 entries. The count is exposed at the top of/tools.html.- The no-display-ads claim is verifiable. View source on any page. You will not find an ad slot, an ads.txt file, an ad network script, or a sponsored-content block. The whole markup is the tool and its text.
- The site is open source. https://github.com/mrpr0phecy/mrpr0phecy. The repo is 47 MB total, including screenshots for the help docs.
- I am one person, based in Luton, UK. I work on this in the evenings and weekends.
- The thing I am most proud of is the “How mortgages really work” guide at https://www.themostusefulsiteintheworld.com/guides/mortgage.html. The bank's calculator never tells you the total interest. The guide walks through it.
If you only click one thing on the site, that guide is the one.
If you want to embed a tool (e.g. on your own site or in a school newsletter),
/embed.htmlgives you a one-line iframe for any of the 562.Happy to answer questions. I read every comment.
Engagement > raw upvotes. Product Hunt's algorithm in 2026 weights the number of comments and the quality of the discussion. A 50-comment post with thoughtful replies ranks higher than a 200-upvote post with no comments. Spend the first 2 hours replying to every comment with a substantive answer.
Hunters, not just makers. Get a hunter (someone with a good PH reputation) to submit the post instead of submitting it yourself. Posts with hunters get 2-3× the page-1 visibility. Ask a maker friend with a 100+ follower count to hunt it.
Avoid the “AI” trap. Don't call it “AI-powered” in the tagline. PH's audience is allergic to the word. The tagline is “562 free browser tools” — no buzzwords.
Don't launch on a Friday or weekend. Tuesday, Wednesday, or Thursday only.
Don't launch on a day with a competitor. Check the PH calendar the day before to make sure no comparable product is launching the same day.
Stagger HN and PH. If you're doing both, launch HN first (Tuesday), then PH 48 hours later (Thursday). Doing both the same day splits the launch energy.
Don't ask for upvotes. Asking in the post gets the post downranked. Asking in a comment is fine if you have given the comment a real, substantive update first.
After 48 hours, record in INCOME.md: