Phone videos are huge — a minute of 4K can be hundreds of megabytes. Messaging apps, email, and upload forms all cap file sizes, leaving you stuck. The fix is re-encoding to a target size: you pick the size you need for where you're sending it, and the encoder distributes the bitrate to hit it.
The faymox video compressor does this with ffmpeg running inside your browser via WebAssembly. Your video never uploads to a server — important, because uploading a 500 MB video to a "free" converter is both slow and a privacy gamble. The first visit fetches the video engine once (about 25 MB, then cached); after that, pick a target size and let it transcode.
Compress MP4 in 3 steps
- Drop your MP4 into the Video Compressor.
- Choose a target size that fits where you're sending it (for example, under your chat app's attachment limit).
- Wait for the transcode to finish, preview the result, and download the smaller MP4.
FAQ
How long does compression take?
It runs on your device, so a modern laptop handles a minute of video in well under a minute. The first visit downloads the encoding engine once (about 25 MB).
Will my video look worse?
Smaller size means lower bitrate, so somewhat — but a modest reduction (say 100 MB to 25 MB) stays very watchable. Halving the size is safer than cutting it to a tenth.
Is there a maximum file size?
You're limited by your browser's available memory rather than an arbitrary cap. For very large files, trim the clip first with the Video Trimmer.