HavenTools
Fast, private developer tools that run in your browser
What it does
HavenTools is a fast, privacy-first collection of developer utilities that run directly in your browser. Format, validate, convert, and work with developer data without unnecessary uploads or server roundtrips.
A lightning-fast, privacy-first suite of developer and utility tools that run entirely locally in your browser. Zero server roundtrips.
Developer tools and everyday utilities — all free, all private. Everything runs in your browser. No signup, no uploads, no tracking. Format, validate, transform, and convert JSON data. All processing runs privately in your browser. Merge, split, extract, rotate, and inspect PDF documents entirely in your browser. No file uploads. Compress, resize, convert, crop, watermark, and inspect images privately in your browser. Visual CSS generators for gradients, shadows, grids, flexbox, transforms, and more. Copy production-ready CSSfrom haventools.dev
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Launched alongside, August 2026
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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