How does the video compressor work?

It uses FFmpeg compiled to WebAssembly, running entirely in your browser. The tool re-encodes the video using H.264 (MP4) or VP9 (WebM) with a configurable quality setting (CRF). No data is ever sent to a server.

What does the quality setting (CRF) mean?

CRF (Constant Rate Factor) controls the trade-off between file size and quality. "High Quality" (CRF 23) gives the best result with moderate compression. "Balanced" (CRF 28) is a good all-around choice. "Max Compression" (CRF 35) achieves the smallest file size with some quality loss.

Are my video files uploaded to a server?

No. All processing happens 100% in your browser via WebAssembly. Your video files never leave your device — complete privacy is guaranteed.

Video Compressor

Compress video files online — reduce file size while keeping great quality. Supports MP4, WebM, MOV, AVI, MKV. 100% in your browser using FFmpeg WASM. Your files never leave your device.

Your data never leaves your device

Frequently Asked Questions

How does the video compressor work?

It uses FFmpeg compiled to WebAssembly, running entirely in your browser. The tool re-encodes the video using H.264 (MP4) or VP9 (WebM) with a configurable quality setting (CRF). No data is ever sent to a server.
What does the quality setting (CRF) mean?

CRF (Constant Rate Factor) controls the trade-off between file size and quality. "High Quality" (CRF 23) gives the best result with moderate compression. "Balanced" (CRF 28) is a good all-around choice. "Max Compression" (CRF 35) achieves the smallest file size with some quality loss.
Are my video files uploaded to a server?

No. All processing happens 100% in your browser via WebAssembly. Your video files never leave your device — complete privacy is guaranteed.