
JoyTools — Free Online Developer Tools
Fast, free online utilities for devs & digital creators
What it does
Free, fast, and 100% privacy-first developer tools. Format SQL, JSON, YAML, convert files, edit PDFs, and generate code — all processing happens locally in your browser.
Does the same job
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- IMI made an online free tool site2025 · ufreetools.com · ▲5
Hi HN! I've created [UFreeTools](https://www.ufreetools.com/), a collection of developer utilities (60+ tools and growing) that's completely free, ad-free, and runs entirely in the browser. No data leaves your device - everything is processed locally. ## Background As a developer, I found myself constantly searching for simple utilities like JSON formatters, UUID generators, and color pickers. Most existing options were cluttered with ads, required sign-ups, or sent data to servers. I wanted clean, fast tools that respected privacy. So I built UFreeTools as a modern SPA using…
ToolsNinja - 100+ free online tools10d ago · toolsninja.dev · ▲1100+ free online dev tools for free to use on daily basis
Everyday Dev Tools12d ago · toolsfordev.tools · ▲1free developer tools that work offline, in your browser

More dev tools this month
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Open-source GTM skills for technical founders
Dev tools · 29d ago · gtmcofounder.com

OpenTrailPaper is open-source bike computer firmware for the LilyGO T5S3 4.7" E-Paper PRO. It supports offline maps, GPX routes, FIT recording and Bluetooth sensors.
Dev tools · 1d ago · opentrailpaper.com

Launched alongside, August 2026
the whole month →- TL
Life & fun · 10d ago · louisabraham.github.io


- SA
Hello HN! I found that picking out plausible but diverse skin tones for my digital art and game development projects was kind of difficult, and I got curious about if there was a way to define a color space that made it easy. I've built a color picker and procedural generation algorithm based on the space as well as a bunch of other fun js features and demos throughout the page that use the equations. If you find it interesting, I have lots of explanations of how I built it and what properties the space has. The methodology might be a bit shaky, but hopefully the result is as helpful for…
Life & fun · Aug 2026 · toneyalexander.github.io


I trained a 125M-parameter transformer to autocomplete piano performances in real time (~108 notes/sec on an iPhone 15). The idea is basically GitHub Copilot or Tabnine, except instead of prompting it with code, you prompt it by playing a few notes on a MIDI piano. The model then continues what you played, entirely on-device. The app is free if anyone wants to try it. Happy to answer questions about the model, training, Core ML, or the many things that didn't work.
AI · 17d ago · simedw.com