How it works

Re-encode a video at lower bitrate or smaller resolution to shrink the file. Output is H.264 MP4.

Three knobs. Quality (CRF 18 to 35, where lower means higher quality and bigger file; 28 is a balanced default). Resolution (keep original, or downscale to 1080p / 720p / 480p / 360p). Audio (96, 128, 192 kbps AAC, or drop audio entirely for video-only output). Optionally trim to a clip range first via the built-in trimmer. The tool runs ffmpeg.wasm with libx264 at the fast preset. A 1080p 100MB MP4 compressed at CRF 28 / 720p typically drops to 15-30 MB with minor quality loss. CRF 23 is closer to source quality but a larger file. CRF 35 is small but blocky for fast motion. Output filename has -compressed.mp4 appended.

How to use it

1. Drop your video. Optionally trim to a clip range first with the built-in trimmer.
2. Set quality and resolution. CRF 28 and 720p is a balanced default; lower CRF means higher quality and bigger files.
3. Choose audio handling. Keep audio at 96-192 kbps AAC, or drop it entirely.
4. Compress and download. ffmpeg.wasm re-encodes locally — expect a few minutes for longer videos — then the -compressed.mp4 downloads.

Frequently asked questions

What CRF should I pick?

23 if quality matters and file size is flexible. 28 (default) for a good balance. 32+ for small files where some blockiness is acceptable.

Why is it slow?

Video re-encoding is CPU-heavy. ffmpeg.wasm is single-threaded in the browser, so a 5-minute video can take a few minutes to encode. For a one-off, that's fine.

Will compressing make the file shareable?

Usually. Dropping a 1080p file to 720p / CRF 28 often gets it under typical email and chat-app limits (25 MB Gmail, 50 MB Discord).

Is the video uploaded?

No. Everything runs locally via ffmpeg.wasm.