Compress Video – Free Online Tool
Reduce video file size while maintaining quality. Compress large video files for easier sharing and faster uploads.
Example Output
Re-encodes with a tunable CRF (Constant Rate Factor). 23-28 is the sweet spot — visually near-lossless at half the size or less.
vacation-compressed.mp4 (240 MB, 1080p H.264, CRF 28) — 80% smaller
What is Compress Video?
Shrink video file size without uploading the file anywhere. The tool runs FFmpeg in your browser via WebAssembly, re-encoding with H.264 (or H.265 / VP9) at a quality level you control. Typical 4-10× size reduction with no perceptible quality loss at CRF 23-28.
Why use this tool?
- No registration, account, or installation required
- No API keys to manage and no rate limits to monitor
- 100% free with no hidden costs or daily limits
- First-load downloads the WASM core once (~30 MB), then subsequent edits are fast
- No video upload — clips of any length stay on your local machine
How to use
- Upload your video file
- Select compression quality level
- Click "Compress Video" to process
- Download the compressed video
Examples
Email-attachment fit
A 1.2 GB phone clip compresses to 90 MB — fits inside a 100 MB Gmail attachment limit with quality intact.
Cloud-storage savings
A folder of 50 family videos halves in size after batch compression, freeing GB of Google Drive / iCloud space.
Faster uploads
A 4K screen recording shrinks 75% before uploading to YouTube — same final quality, 4× faster upload.
Common use cases
- Fitting videos into email / chat attachment limits
- Reducing cloud-storage footprint
- Speeding up uploads to YouTube / Vimeo / social media
- Preparing videos for low-bandwidth viewers
- Archiving home videos without losing quality
Troubleshooting
- Output looks soft or blocky
- CRF is too high — lower it (smaller number = better quality). Try CRF 23 for visually lossless, 28 for "good enough" web quality.
- Compression takes forever
- WASM FFmpeg is single-threaded. For large 4K files, drop resolution to 1080p before compressing, or use the "fast" preset (smaller savings, much faster).
- Audio out of sync after compression
- Switch container to MP4 (not MKV) and pick AAC audio. Rare A/V drift is usually a container-level issue, not codec-level.
Frequently Asked Questions
Our compression algorithm balances file size reduction with quality preservation. You can adjust compression settings to find your preferred balance.
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