
OJF - Online JSON Formatt
Dev tools that never touch your data. Format, convert, fix.
What it does
Problem: Developers often deal with messy JSON, XML, and Parquet data broken APIs, unformatted configs, and format conversions. Many online tools upload data, require sign-ups, or fail on large files. Solution: Online JSON Formatt is a free browser-based toolkit with 20+ tools that format, validate, compare, convert, and fix data locally. Built with Rust-WASM and Web Workers, it handles 100MB+ files without freezing your browser.
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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 · 16d ago · simedw.com