Video Compressor
Reduce video file size right in your browser. Nothing is uploaded — your video never leaves your device.
Drop your video here
or click to browse your files
Supports MP4, MOV, WebM, MKV — processed entirely on your device
A video straight off a modern phone can easily be several hundred MB to a few GB, which makes it slow to upload, share over WhatsApp or email, or attach to a website. The Video Compressor shrinks MP4, MOV, WebM and MKV files by re-encoding them at a lower bitrate, cutting file size significantly while keeping the video watchable at normal resolutions.
Unlike the online compressors most sites offer, nothing here is uploaded to a server. Compression runs entirely inside your browser using a WebAssembly build of FFmpeg — the same open-source engine that powers most professional video tools — so a multi-GB file never has to travel over the internet just to get smaller.
Because everything happens on your device's CPU rather than a remote server, larger files take real time to process, especially on older phones or laptops. There's no queue and no daily limit, but expect a multi-minute wait for long or high-resolution videos.
Step-by-step instructions
- 1
Upload your video
Click the upload area or drag an MP4, MOV, WebM or MKV file directly onto it.
- 2
Wait for processing
The video is compressed locally in your browser — a progress bar shows how far along the encode is.
- 3
Preview and download
Once finished, play the result inline to check quality, then download it as an MP4.
Common use cases
WhatsApp and messaging limits
Most messaging apps compress or reject large videos automatically — shrinking a clip first keeps you in control of the quality trade-off.
Faster uploads
A smaller file uploads faster to social media, cloud storage, or a website — useful on slow or limited mobile data.
Email attachments
Email providers typically cap attachments around 20-25MB; compressing a short clip first can get it under that limit.
Saving device storage
Compressing old recordings before archiving them frees up phone or laptop storage without deleting the footage.
Tips for best results
- If the result is still too large, the video's original resolution is usually the biggest factor — very high-resolution source footage (4K) will still produce a bigger file than 1080p footage at the same quality setting.
- Processing time scales with video length and resolution, not just file size — a short 4K clip can take longer to compress than a long but low-resolution one.
- Keep your original file until you've confirmed the compressed version looks acceptable, since compression is lossy and can't be reversed.
Frequently asked questions
Does this tool upload my video anywhere?
No — compression runs entirely in your browser using WebAssembly; the video file never leaves your device.
Why is compression taking a long time?
Video encoding is CPU-intensive and runs on your device's processor instead of a server, so longer or higher-resolution videos take longer, especially on older phones.
What formats can I upload?
MP4, MOV, WebM and MKV are supported as input; the compressed output is always delivered as MP4 for broad compatibility.
Will compressing reduce the resolution too?
This tool reduces bitrate (quality per frame) rather than resolution, so the frame size stays the same while file size drops.
Is there a file size limit?
There's no hard limit, but very large files (roughly 250MB+) can be slow or run into memory limits on mobile devices — a desktop browser handles large files more reliably.