Free video compressor (local file)
Shrink video files privately in your browser — no upload and no account required. Supports MP4, MOV, WebM, MKV, M4V, AVI, and other common video types; outputs a smaller, widely compatible H.264 MP4 with AAC audio.
How to use this tool
- 1
Open Video compressor
Use it to shrink local video files in-browser and download an MP4.
- 2
Choose a video file
Select a local video and wait for the engine to load on first use.
- 3
Download the MP4
Check the size line, then download the compressed MP4 to your device.
Quick facts
| Runs offline? | After the engine loads once, encoding can run without uploading your file. |
|---|---|
| Upload to a server? | No. Bytes stay in your browser tab. |
| Local files only? | Yes — select a video stored on your device. |
| Output format? | MP4 with H.264 video and AAC audio. |
Top use cases
- Compress video files in-browser, H.264 MP4 output, nothing uploaded.
- Runs offline?: After the engine loads once, encoding can run without uploading your file.
- Upload to a server?: No. Bytes stay in your browser tab.
- Local files only?: Yes — select a video stored on your device.
- Output format?: MP4 with H.264 video and AAC audio.
FAQ
Does my video leave this device?▾
No. The file is read and written locally in your tab.
Why is the first run slow?▾
The browser downloads the FFmpeg engine once (~30 MB). Later compressions in the same session are faster.
Will the file always get smaller?▾
Only when re-encoding saves bytes. If the source is already very small, the tool reports that compression did not help.
Mobile browsers?▾
Modern phones work for short clips; long or large videos are smoother on desktop Chrome or Edge.
Maximum file size?▾
Up to 200 MB and about 10 minutes per clip, limited by device memory.
Which browsers work best?▾
Current Chrome, Edge, Firefox, and Safari versions work best for local video encoding.