Media Tools
Video Compressor
Compress a video to a smaller MP4 right in your browser.
Runs in your browser Your input never leaves your device.
About this tool
Choose a video and set the quality value (CRF, from 18 to 40, default 28). Press Process and the video is re-encoded as H.264 MP4 using ffmpeg compiled to WebAssembly, so it runs entirely in your browser and the video is never uploaded. A higher CRF number gives a smaller file with lower quality; lower numbers keep more quality but save less. Compression is lossy, so some quality loss is unavoidable. The first run downloads the ffmpeg engine (about 25 MB), and it is slower than desktop software because it runs in a single browser thread, so large files can take a long time or run out of memory.
How to use it
- Drop a video or choose a file.
- Set Quality (CRF); try 28 first, higher for smaller files.
- Press Process and wait for the progress bar to finish.
- Check the size, preview the result and press Download.
Common problems
- It is slow or the browser tab stops
- Processing happens on your device in one thread. Try a shorter clip, close other tabs or raise the CRF.
- The first run takes a long time
- The ffmpeg engine of about 25 MB is downloaded the first time. Later runs on the same page load reuse it.
- The result is not much smaller
- Already well-compressed videos have little to save. Increase CRF for a bigger reduction, at the cost of quality.