Compress Video Online — Free, No Upload
Make a video file smaller without a visible drop in quality.
Drop a file here
or click to choose a file
Runs on your device Your file is processed by your own browser and is never uploaded to a server.
Short answer
A video can be compressed for free in a web browser without uploading it anywhere. The file is re-encoded to H.264 at a higher constant rate factor, which typically reduces size by 50–80% while keeping the resolution unchanged. Because the work happens locally via WebAssembly, there is no file size cap and the video never leaves the device.
At a glance
| Accepts | MP4, MOV, MKV, AVI, WebM |
|---|---|
| Produces | MP4 (H.264 / AAC) |
| Processing | In your browser |
| Price | Free, no limits |
| Account | Not required |
Most video files are far larger than they need to be. Phone cameras and screen recorders optimise for capture speed rather than storage, so they write a very high bitrate that carries almost no visible detail. Re-encoding that footage at a sensible quality target usually removes half to four fifths of the file size before the difference becomes noticeable.
The Balanced setting is the right default for almost everything you would email, upload or archive. Choose High when the video will be edited further, since each re-encode compounds quality loss. Choose Small only for previews and drafts.
How to use it
- 1
Add your video
Drop a video file onto the box, or click it to browse. The file stays on your device.
- 2
Pick a quality level
Balanced suits most uses. High preserves more detail; Small produces the smallest file.
- 3
Start the compression
The engine loads once, then re-encodes the video. Progress is shown as a percentage.
- 4
Download the result
Save the compressed MP4. The original file is untouched.
Frequently asked questions
Does compressing a video reduce its quality?
Yes, video compression is lossy, but at the Balanced setting the loss is usually invisible at normal viewing distance. The resolution and frame rate are preserved; only the bitrate is reduced.
Is there a file size limit?
There is no server-side limit because nothing is uploaded. The practical ceiling is your device memory. Files up to about 500 MB work comfortably on a typical laptop; very large files are slower and may fail on phones.
Is my video uploaded to a server?
No. The compression runs inside your browser using WebAssembly. No copy of the file is transmitted, stored or seen by anyone else.
Why is it slower than a desktop app?
Browser-based encoding runs in a sandbox on a single thread, so it is several times slower than native software. The trade-off is that nothing needs to be installed and nothing is uploaded.
Which formats can be compressed?
MP4, MOV, MKV, AVI, WebM and most other common containers can be read. The output is always MP4 with H.264 video and AAC audio, which plays on virtually every device.