PureDevUtils
Free browser-based dev tools that never upload your data.
What it does
Free browser-based developer tools for JSON, JWT, Base64, URL, UUID, and CSV — format, validate, encode, decode, and convert data privately, with nothing uploaded.
Does the same job
all alternatives →
- DADevUtils.app – Developer Utilities for macOS2020 · ▲241
This is a project I've been working on since the start of Covid-19. I built an app so that I don't have to put data into online tools like JWT debugger, JSON formatter, URL decoder, etc... https://devutils.app The app works entirely offline and is open-source. I'm selling the pre-built version of the app to earn some revenue for my time. If you want to try the app but can't afford the price or don't have XCode to build the app, drop me an email (my profile), I'll be happy to provide you a free build. I would love to hear all the feedback/suggestions. Thanks!


Everyday Dev Tools12d ago · toolsfordev.tools · ▲1free developer tools that work offline, in your browser
More dev tools this month
the category →



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

Lettertrace▲375Track your AI visibility for free (using your own API keys!)
Dev tools · 25d ago · lettertrace.com
Launched alongside, August 2026
the whole month →- TL
Life & fun · 9d 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 · 16d ago · simedw.com