Video Compressor
Compress videos and reduce file size.
Drop your Video file here
or click to browse · max 500 MB
Settings
Slower = better compression, longer conversion time
128k for speech · 192k for general use · 320k for music
FFmpeg WASM (~25MB) will be downloaded on first use and cached by your browser.
Video Compressor
Compresses video files by re-encoding with H.264 and adjustable quality control via CRF (Constant Rate Factor). The CRF value determines the quality-vs-size tradeoff: lower values produce higher quality (larger files), higher values produce smaller files with more compression.
What is it used for?
- Reducing file size for email attachments (most email services limit to 25MB)
- Optimizing videos for web uploads and faster page loading
- Saving cloud storage space on Google Drive, Dropbox, iCloud
- Meeting social media file size limits
- Creating web-optimized versions of high-quality recordings
Step-by-Step Guide
- Upload your video file (MP4, WebM, AVI, MOV, MKV supported)
- Adjust CRF in the settings (18=best quality, 51=smallest file)
- Choose encoding speed preset (faster=quicker, slower=better compression)
- Click Convert to compress the video
- Compare original and compressed file sizes, then download
How it works
Upload a video file and adjust the CRF quality slider. Default CRF 28 offers a good balance. Click Convert and FFmpeg WASM compresses the video using H.264 with the fast preset. Preview and compare the file size reduction.
Tips & Best Practices
- Start with CRF 28 and increase if you need smaller files, decrease if quality isn't good enough
- The 'fast' preset is recommended for browser-based conversion - 'slow' and 'veryslow' will take much longer
- Audio bitrate of 128kbps is fine for speech content, use 192kbps for music videos
Frequently Asked Questions
What CRF value should I use?
CRF 23 is visually lossless for most content. CRF 28 (default) is good for web sharing. CRF 32-35 for minimum file size with acceptable quality. CRF 18-20 for professional/archival quality.
How much smaller will my video be?
Depends on the original encoding. Uncompressed or poorly encoded videos may shrink by 80%+. Already compressed videos (H.264 CRF 23) may only shrink by 20-30% with a CRF increase.
Does the encoding preset affect quality?
The preset only affects encoding speed vs compression efficiency. 'Slower' presets produce slightly smaller files at the same quality but take much longer. 'Fast' or 'medium' are recommended for browser use.
Privacy & Security
This tool uses FFmpeg compiled to WebAssembly (WASM). The WASM binary (~25MB) is downloaded from a CDN on first use and cached by your browser. All file processing happens locally on your device - your files are never uploaded to any server. This makes it safe for sensitive, private, or confidential media files. Large files may take longer to process depending on your device's CPU and available memory.