Reduce video file size. Free, private, runs in your browser.
100% private — your files and text never leave your browser. All processing happens locally on your device.
Choose a file
or drop it here
Lower CRF = better quality + larger file. 18 = visually lossless, 28 = default, 40 = small file.
Video compression reduces file size by applying more efficient encoding, lowering resolution, adjusting bitrate, or a combination of these techniques. Modern video codecs like H.264 and H.265 use sophisticated algorithms to discard visual information that viewers won't notice, achieving dramatic size reductions.
Raw and high-bitrate videos can be enormous — a 1-minute 4K clip can exceed 500MB. Compression makes videos practical to share via email, upload to social media, embed on websites, and store on devices with limited space. Many platforms also have upload size limits that require compression.
Convertful uses FFmpeg compiled to WebAssembly to re-encode your video in your browser. It applies H.264 encoding with optimized settings to reduce file size while maintaining visual quality. You can adjust the compression level to balance quality against size. No server upload is involved.
Yes. Video processing happens entirely in your browser using FFmpeg WASM. Your video files never leave your device.
Typically 40-70% size reduction depending on the content and quality settings.
MP4, WebM, MOV, AVI, MKV, and M4V. All processing happens in your browser using FFmpeg.
You can choose the compression level. Medium compression maintains good quality with significant size reduction. Higher compression saves more space but may reduce quality.