Convert WebM to MP4 without uploading your video
WebM is common for screen recordings and web downloads, but it won't play in a lot of apps, editors, and messaging tools that expect MP4. This converter transcodes WebM to MP4 (H.264) directly in your browser, so you get a universally compatible file without sending your video to anyone's server.
Turn a clip into a GIF
Choose GIF as the output to turn a short WebM or MP4 clip into an animated GIF — great for reactions, demos, and bug reports. GIFs are generated at a reduced frame rate and width to keep them shareable; shorter clips make the best GIFs.
Private by design
Conversion uses a WebAssembly build of FFmpeg that runs on your own device. Because nothing is uploaded, your footage stays private and the tool costs nothing to run. The trade-off is that your phone or laptop does the work, so very large or long videos are slower and are best handled on a desktop browser. Need images instead? Try the KOSEC image converter.