How to use this tool
- Choose your file or try the example.
- Run the tool and check the result.
- Save the result where a download is available.
Supported features & limits
Local single-thread FFmpeg WASM. First use downloads about 31 MB of converter code from this site. Maximum 50 MB input, 60 seconds duration and 4096×2160 source pixels. Output fits within 1280×720, keeping aspect ratio. Includes first video and optional first audio track. Metadata, subtitles, extra tracks and HDR are not preserved. Conversion stops after the time limit; no upload.
What happens to my files?
Your browser reads the file locally. File contents are not sent to our server. Closing or resetting this page clears the working result. Downloaded copies remain on your device.
Maintained by Roman Zmazhenko. Updated 1 November 2026.