StackTools
Private PDF and image tools that never leave your browser
What it does
A free, private alternative to upload-based PDF and image suites. StackPDF: 34 tools to merge, split, compress, convert, OCR, redact, sign, and protect PDFs. StackImage: 18 tools to compress, convert (including HEIC), crop, remove backgrounds, and upscale - all in the browser. No account. Files never leave your device.
StackTools is a family of free, privacy-first apps that run entirely in your browser. StackPDF and StackImage process files on your device — no account, no uploads.
Private browser tools for everyday work . A growing suite of free apps for PDF and images — built so work never requires giving up your documents. Each product is a focused toolkit. Same privacy promise across the family. Merge, split, compress, convert, OCR, redact, and more — free PDF tools that process files on your device. No account. No uploads. Compress, convert, crop, and enhance images privately in your browser — including HEIC convert, background removal, and on-device upscale. No account. No uploads. Files are processed in your browser. Nothing is uploaded to our servers. Open a tool and get to work — no signup, no credit card, no friction. After the first visit, many tools keep…from stacktools.studio
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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