Video Compressor — Reduce Video File Size
Compress MP4 videos with CRF-based quality presets. Choose from High Quality to Max Compression to find the perfect balance of size and quality. 100% client-side — nothing leaves your browser.
How to Use the Video Compressor
- Upload a video — drag an MP4 file onto the drop zone.
- Select quality — choose from four CRF-based presets.
- Review estimate — see the estimated output size based on your preset.
- Compress — click Compress and wait for the process to complete (may take minutes).
- Download — save the compressed file. Compare before/after sizes.
How CRF Compression Works
CRF (Constant Rate Factor) is ffmpeg's quality-based encoding mode. Lower CRF values produce higher quality and larger files; higher values produce smaller files with more compression artifacts. The range 18-32 covers the useful zone:
- CRF 20 — visually lossless or near-lossless
- CRF 26 — good quality with moderate compression
- CRF 30-32 — aggressive compression, suitable for messaging or email