I built 50+ free browser tools that run without uploads, servers, or accounts

I built 50+ free browser tools that run without uploads, servers, or accounts I spent the last few months building NexaTools — a suite of 50+ browser-based tools that do everything from converting images to generating PDFs, testing regex, and transferring files between devices. The key constraint: most tools never send your data to a server. Why I built this I kept using online file converters that required uploading files to unknown servers. For sensitive documents, screenshots, or anything with metadata — that's a problem. I wanted tools that: Run entirely in the browser (client-side) Work offline after first load (PWA) Have no file size limits Don't require accounts, sign-ups, or even JavaScript frameworks Handle real-world tasks (not just demos) What's in it Media tools Image Converter — WebP, PNG, JPG, AVIF, GIF via Canvas API Video Converter — MP4, WebM, MKV, AVI using FFmpeg WebAssembly Audio Converter — MP3, WAV, OGG, FLAC, AAC with bitrate control EXIF Stripper — Remove GPS and camera metadata from photos Background Remover — TensorFlow.js-based AI background removal PDF tools Merge, split, rotate, delete pages Add watermarks and page numbers Convert images to/from PDF Redact sensitive text permanently Developer tools JSON Formatter — with syntax error diagnostics Regex Tester — live match highlighting and capture groups Code Formatter — JS, TS, JSON, HTML, CSS, Python Hash Generator — MD5, SHA-1, SHA-256, bcrypt Base64 Image Encoder/Decoder Diff Checker, URL Encoder, Markdown Editor Utility tools P2P File Transfer — WebRTC peer-to-peer, no server relay Scientific/Graphing Calculator Currency Converter — 150+ currencies, live rates QR Code Generator/Scanner Password Generator — cryptographically secure Word Counter, Pomodoro Timer, Age Calculator Microsoft Store Link Generator APK Side Loader URL Shortener Technical approach The stack is simple: Frontend: Vanilla HTML/CSS/JS + React for the main app shell Media processing: FFmpeg compiled to WebAssembly (runs in browser) File transfer: WebRTC with a lightweight signaling server PDF manipulation: Client-side libraries Backend: Node.js + Express for URL shortener, file transfer signaling, and donations only The interesting part is how FFmpeg WebAssembly works. The entire FFmpeg binary (~25MB) loads into the browser's memory and processes video/audio locally. This means: No upload/download cycle for conversion Works on files larger than what most free converters allow No server costs (beyond hosting the static frontend) For file transfer, I used WebRTC to establish direct browser-to-browser connections. The signaling server only helps devices find each other — the actual data transfer happens peer-to-peer. What I learned WebAssembly is production-ready. FFmpeg WASM handles real files without crashing. PWA caching is tricky. You need careful cache invalidation for updated tool logic. Privacy-first is a real differentiator. Users actually care about where their files go. Simple tools win. The word counter and QR generator get more usage than the fancy stuff. What's next More blog posts explaining the privacy model Adding offline support to the URL shortener Community-contributed tools Open-sourcing the WebAssembly build pipeline Try it: nexatools.in — free, no accounts, works offline. I'd love feedback on the tools or the technical implementation. What browser-based tools do you wish existed?