MP4 compressor
Compress an MP4 without uploading it.
Shrink an MP4 file locally and download a smaller MP4 result. Useful when an MP4 is too large to send, post, or attach.
Compress MP4
Create a smaller MP4 with simple quality and resolution controls.
Your selected video is processed in this browser tab. It is not uploaded to a conversion server.
Ready.
Why MP4 files get large
MP4 size depends on video length, resolution, frame rate, motion, and bitrate. This tool creates a new MP4 with smaller encoding settings.
Best settings and limits
Best first try
Balanced and 720p is a good first pass. Pick Smallest file for chat apps or attachment limits.
When this may fail
Some MP4s are already highly compressed. Those files may not shrink much without visible quality loss.
Privacy boundary
The selected video file stays on your device while the tool creates the output.
Frequently asked questions
Can I compress MP4 offline?
This page runs in the browser after the site loads. The selected MP4 is not uploaded for conversion.
Will the output still be MP4?
Yes. The result is an MP4 file.
Why did my file get bigger?
If the source was already very compressed, re-encoding can sometimes increase size. Use stronger compression settings.