Free Online Video Compressor — Reduce Video File Size
Compress your videos online with our free video compressor powered by FFmpeg WebAssembly. Upload any video, adjust the CRF value for quality/size balance, choose output resolution, and re-encode everything locally in your browser using the H.264 codec for broad compatibility. No file uploads to servers, no watermarks. Perfect for reducing video file sizes for sharing, email, or web publishing.
Upload the video file you want to compress.
Adjust CRF and resolution settings to balance quality and file size.
Download your compressed video and see exactly how much space was saved.
Tips for Compressing Videos
- CRF 23 is a good starting point for H.264 — balances quality and file size. Lower (18-22) for higher quality, higher (28-32) for smaller files.
- CRF 23 is the default for H.264 — a well-balanced starting point. Lower (18-22) for higher quality, higher (28-32) for smaller files.
- Reducing resolution (e.g., 1080p to 720p) dramatically reduces file size. Use this when full HD is not required.
Frequently Asked Questions — Video Compressor
Is the video compressor free?
Yes, completely free. No registration, no hidden charges, and no watermarks. All processing happens locally in your browser using FFmpeg WebAssembly.
How does CRF affect compression?
CRF (Constant Rate Factor) controls quality. The range is 0-51, where lower values mean better quality but larger file size. For H.264, 23 is the default, 18 is visually lossless, and 28 is acceptable for web use.
What video formats are supported?
FFmpeg supports virtually all video formats including MP4, WebM, MOV, AVI, MKV, FLV, and many more. The compressed output is in MP4 format.
Why does the first load take time?
The first time you use the tool, it needs to download the FFmpeg WebAssembly core (~30 MB). This is cached by your browser for subsequent use, so later loads are much faster.
What codec does this tool use?
This tool uses H.264 (AVC) encoding, the most widely compatible video codec. H.264 works on virtually every device made in the last 15 years and offers excellent compression quality.
Is there a file size limit?
There is no hard limit, but very large files (over 500MB) may be slow to process due to browser memory constraints. For best results, compress videos under 200MB.