Video Compressor
Runs in your browser. Your files never leave your device.
How we keep your files private
How to use Video Compressor
- Add your video.
- Choose quality and maximum height.
- Wait for encoding, then download the MP4.
Common uses
- Making videos small enough to share.
- Saving storage.
- Speeding up uploads.
About this tool
Compress video with FFmpeg compiled to WebAssembly (x264, CRF-based). Choose a quality level and a maximum height; the output is an MP4 with H.264 and AAC. The engine (about 30 MB) downloads once and is cached.
Tips and limits. Encoding runs on your device with WebAssembly, on a single thread. Expect it to be slower than desktop apps; short clips take seconds to minutes, long or 4K videos can take much longer or run out of memory on phones.
Worked example
A 100 MB phone video at 1080p can often drop to 20 to 40 MB at 720p with little visible loss on a phone screen, but the exact result depends on the content.
Common problems and fixes
- Very slow or out of memory.
- Compression runs on your device. Use a desktop browser for large files and close other tabs.
- The first run takes a while.
- The video engine (about 30 MB) downloads once and is cached afterwards.
- Quality looks poor.
- Choose a higher quality or resolution option.
Next steps
Frequently asked questions
Why is it slow?
The encoder runs in your browser on one CPU thread. Use a desktop for long videos.
What format is the output?
MP4 with H.264 video and AAC audio.
Will quality drop?
Yes, compression is lossy; a higher quality setting keeps more detail.
Are my files uploaded to a server?
No. Everything runs inside your browser on your own device, so your files and text are never sent anywhere.
Is it really free?
Yes. There is no sign-up, no watermark and no limit on how often you use it.
Does it work on my phone?
Yes. It works in any modern browser on phones, tablets and computers. Very large files may be slow on older phones.