Target: daily.dev (the developer-focused content platform with ~1M MAU) When: the same day as the Show HN post, 3-4 hours after HN goes up Why daily.dev: it surfaces posts to developer audiences that don't read HN, and the upvote/downvote system is more forgiving than HN for less-known projects.
Title: I built 562 free browser-side tools in 2 years. Vanilla JS, no build, no npm.
URL: https://www.themostusefulsiteintheworld.com
Tags: #tooling #opensource #showdev #javascript
Cover image: the og-tools.png at the top of the site, or a screenshot of the catalogue at /tools.html
I'm a developer in Luton, UK. For the last 2 years I've been building a site with 562 free browser-side tools — mortgage calculator, BMI, compound interest, password generator, BPM tapper, JSON formatter, eyepiece calculator, sleep cycle planner, colour contrast checker, invoice generator, and 550+ more.
The whole thing is vanilla JavaScript, no framework, no build step, no npm, no TypeScript, no bundler. Each tool is one HTML file. The total repo is 47 MB, of which ~14 MB is the tools themselves and the rest is screenshots for the help docs.
The architecture in 60 seconds:
cards/<tool-name>.html— one file per tool, 562 filescards/cards.json— a single JSON file with all 562 entries (id, name, title, description, category, file)index.html— the home page, driven by the JSON, with a client-side category filtertool.html?card=<name>— a shim that reads the URL and injects the tool- A build script that runs on my laptop before I push and regenerates the sitemap, RSS, llms.txt, related.json, and the home page from the JSON
The no-display-ads part: I made a deliberate choice to ship no ad networks, no retargeting pixels, no sponsored-content blocks, no upsell modals. View source on any page and you will not find an ad slot — because the markup is the page, and the page is the tool. (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 of them are advertising.)
Open source: The repo is at https://github.com/mrpr0phecy/mrpr0phecy. The contribution guide is in
CONTRIBUTING.md. The issue templates are pre-filled for tool requests, bug reports, and content/SEO feedback. About 30 outside contributors in 2 years.What I'd love feedback on from this community:
- Is the JSON-driven architecture sustainable? Adding a tool is a 3-step process (write the HTML, add a JSON entry, run the build). It's been great for me as a solo dev, but I am not sure it scales to a 10-person team.
- Should I add a PWA / service worker for offline use? It's on the list but the cost-benefit hasn't been obvious.
- Any tools you think are missing? The most-requested categories are: more music-theory, more UK tax/NIC, more craft (knitting/crochet), more small-business invoicing, more sleep/circadian, more accessibility (screen-reader-first).
Happy to answer any questions. The site is non-commercial; the donate link has made £34.50 in 9 months.
Russell.
Use the right tags. The 4 tags above are the ones the daily.dev audience scans. Avoid tags like #career or #fun — they are noisier.
Post in the morning (your time, but ideally 09:00-12:00 UTC). daily.dev's traffic peaks in the European and US morning.
Reply to comments within 4 hours. daily.dev surfaces recent, active comments higher in the feed.
Don't cross-post more than once. A daily.dev post that is also on HN and Reddit is fine if the URLs are different, but don't post the same content twice on daily.dev.
Use a real screenshot in the cover image. The og-tools.png or a screenshot of /tools.html works. Posts with custom cover images get ~2× the click-through.
After 48 hours, record in INCOME.md: