Why Tools Ku
- 100% free, no signup
- ffmpeg.wasm local transcoding
- Tune resolution and CRF for size vs quality
- For social, email, and web uploads
Phone clips and screen recordings are often too large to share. Re-encode in-browser with ffmpeg.wasm—lower height and raise CRF to cut size.
Higher CRF = smaller file, lower quality (often 23–32). Local-only but CPU-heavy; allow time for progress to finish.
Steps
- Upload the video
- Set max height (720p, 1080p, etc.) and CRF
- Start compress and wait for local ffmpeg
- Preview and download the result
FAQ
- Video uploaded?
- No—ffmpeg.wasm runs entirely in your browser.
- Supported formats?
- Common types like MP4, WebM, MOV—depends on browser/ffmpeg support.
- CRF value?
- ~23 keeps quality; 28–32 smaller for sharing. Re-run if needed.
- Why so slow?
- Transcoding is heavy—longer/higher-res takes more time. Use desktop Chrome/Edge.
- Audio sync issues?
- Usually synced; bad sources or low memory may glitch—try shorter clips or lower resolution.
- Other video tools?
- Try Video to MP4, Trim, to GIF, or Extract Audio.