How does browser-based video compression work?

This tool uses FFmpeg.wasm to re-encode your video using H.264 with a higher CRF (Constant Rate Factor) value. A higher CRF value means more compression and smaller file size, at the cost of some quality. The default setting (Medium) provides a good balance for most videos.

Is my video uploaded to a server?

No. FFmpeg.wasm runs entirely in your browser. Your video is processed locally and never sent to any server.

How much can I reduce a video file size?

Compression results vary by video content. Typically you can expect 30–70% reduction. Videos with lots of static scenes compress more than fast-moving action content.

Will compression reduce video quality?

Some quality loss is inevitable with compression. The Low compression setting preserves near-original quality. Medium provides good balance. High compression reduces quality more noticeably but achieves the smallest file size.

Compress Video Online for Free

Reduce video file size without sacrificing too much quality — browser-based H.264 compression, no upload.

Your Privacy is Protected

Your files are processed entirely in your browser
No file upload — your video never leaves your device
No account or registration required
Files are not stored on any server

Supported Formats

Input Formats

MP4MOVWebMAVI

Output Format

✓ MP4

Frequently Asked Questions

: This tool uses FFmpeg.wasm to re-encode your video using H.264 with a higher CRF (Constant Rate Factor) value. A higher CRF value means more compression and smaller file size, at the cost of some quality. The default setting (Medium) provides a good balance for most videos.

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