No upload · No size limit · No watermark · No signup
Compress video online — free, private, no upload
Shrink MP4, MOV and WebM files without losing the quality that matters. Everything runs locally in your browser with WebCodecs — the video is decoded, re-encoded and muxed on your device and never leaves it. Pick a quality preset, or target a size for Discord, email or WhatsApp so the file lands under the limit.
How it works
- Drop a video file. It stays on your device the whole time.
- Pick a preset — same quality, balanced or smallest — or target a size instead: Discord, Email, WhatsApp or a custom MB value.
- Press compress and watch the progress bar.
- Download the result and compare the sizes — target runs also show whether you landed under the limit.
Frequently asked questions
Is my video uploaded to a server?
No. Decoding, re-encoding and muxing all happen inside your browser using WebCodecs and mediabunny — the video file never leaves your device, even for huge files, because it's read and written in small chunks instead of all at once.
What's the difference between the three presets?
Same quality lowers the bitrate just enough to shrink the file 30-50% with no visible change. Balanced targets about 70% smaller, a good tradeoff for sharing. Smallest pushes for 85-90% smaller, prioritizing file size over quality — best for slow connections or strict upload limits.
What formats does it accept, and what do I get back?
Drop an MP4, MOV, WebM or MKV file. The output is always an H.264 video inside an MP4 container, the most widely compatible combination, and the original audio track is copied over unchanged rather than re-encoded.
Why does my browser say it isn't supported?
This tool needs WebCodecs, specifically a working H.264 video encoder, which current Chrome, Edge and Firefox on desktop or Android provide. Every browser on iPhone and iPad shares Apple's WebKit engine, which doesn't expose one yet, so the compressor is unavailable there.
Is there a file size limit?
No hard limit from the tool itself — it streams the file in chunks rather than loading it whole. In practice you're bounded by your device's available memory and processing time, and very large files simply take longer to compress.
What does the "target a size" section do?
Instead of picking a quality preset, click Discord, Email or WhatsApp to prefill a target size with headroom under that platform's real upload limit, or use Custom to type your own MB value. After compressing, an indicator tells you honestly whether the result landed under the limit.