Building KeepSimp: free browser tools for PDFs, video and images that never upload your files

Suraj Kumar • Peerlist

KeepSimp is a free website of 71 tools for everyday files, and every one of them runs in your browser. Your files are opened and written on your own device and never uploaded. There is no account, no sign-up and nothing to pay for.What it does: edit the words already on a PDF page, sign, fill and create forms, redact for good, OCR scans, merge, split, compress, and convert to and from Word, Excel and PowerPoint. Convert, trim, crop and compress video, make reels, clean up sound, set loudness, and transcribe speech with Whisper. Remove backgrounds, compress, resize, convert, upscale and edit photos. For developers: a code playground, an API client, a JSON formatter, regex, JWT and hash tools. And everyday tools: calculators, a unit converter, timers, a typing test, printables and a few games.How it works: the heavy work runs in WebAssembly and web workers on your device (MuPDF for PDFs, the browser's own video encoders, Whisper for speech, small AI models for backgrounds). The site is a static Next.js export with no server to receive anything. It installs as an app and works offline once installed, and AI agents such as Claude Code and Cursor can use the same tools through the keepsimp-mcp bridge on npm.