# nothing leaves your browser
Developer tools that run in your browser
Utilities that process everything locally. You can paste production logs, session tokens or payloads holding customer data: none of it leaves your machine.
Tools
# json & data
# encoding
# binary
# time
# security
# text
# color
# web
# video — ffmpeg in wasm
- trim-videoTrim Videocuts a section without uploadinglocal
- merge-videoMerge Videosjoins several files into onelocal
- extract-audioExtract Audio from Videotrack to mp3, m4a or wavlocal
- video-to-gifVideo to GIFclip to GIF with optimised palettelocal
- compress-videoCompress Videoshrinks by CRF qualitylocal
- resize-videoResize Videochanges resolution and crops the area, visuallylocal
- speed-videoVideo Speedspeeds up or slows down, with instant previewlocal
- media-studioVideo and Audio Editortimeline and chained operationslocal
- convert-videoConvert Videomp4, webm and movlocal
- rotate-videoRotate Video90°, 180°, fliplocal
- mute-videoRemove the Audio from a Videomutes the videolocal
# audio — ffmpeg in wasm
29 tools · 29 local
No tool matches the filter.
Why this matters
Most online utilities send whatever you paste to their backend. For a sample JSON, fine. For a production JWT — which is a live credential — or a log holding customer data, that is a leak. Here the processing happens in JavaScript in your browser. The network tab is not empty: the page loads its own fonts and scripts. What it never shows is your content going out, because it never enters a request.
Who maintains this
I am a backend and fullstack developer working with Django, Python and server infrastructure. I built these tools because I use every one of them daily, and it bothered me to paste production data into a site that processes it on someone else server.