Video Compressor
Compress video files by up to 90% directly in your browser. Adjustable quality, resolution, and codec. 100% private — your video never leaves your device.
Upload Video
Drop your video here or click to browse
Supports MP4, WebM, MOV, AVI, MKV, FLV, WMV, 3GP
100% Private — Your Video Never Leaves Your Browser
All compression happens locally using FFmpeg WebAssembly. No file is uploaded to any server. Open your browser's Developer Tools → Network tab to verify there are zero upload requests.
How It Works
Upload Your Video
Drag & drop or browse. Supports MP4, WebM, MOV, AVI, MKV and more.
Adjust Settings
Choose CRF quality level, target resolution, codec, and audio bitrate.
Compress In-Browser
FFmpeg WASM re-encodes your video locally. Watch the progress bar.
Download & Compare
See before/after sizes and download your compressed video instantly.
Quick Answer
Our free video compressor reduces video file sizes by 30–90% using FFmpeg (H.264/H.265) running entirely in your browser — no upload required. Adjust the CRF slider (18 = high quality, 28 = small file), choose a target resolution (1080p, 720p, 480p, 360p), and optionally reduce the audio bitrate. Lower CRF values preserve quality; higher values produce smaller files. Your video never leaves your device, making this the most private way to compress video online.
How It Works
Upload your video by clicking the drop zone or dragging a file onto it. Supported formats include MP4, WebM, MOV, AVI, and MKV.
Adjust the compression settings: move the CRF slider lower for higher quality or higher for a smaller file. Optionally select a lower target resolution or reduce the audio bitrate.
Click "Compress Video" and wait for the in-browser FFmpeg engine to process your file. A progress bar shows real-time status.
Review the before/after file size comparison and download your compressed video. Your original file is never uploaded.
Key Facts
- 100% client-side: your video is processed in your browser and never uploaded to any server
- CRF (Constant Rate Factor): 18 = visually lossless, 23 = default, 28–32 = small file
- H.264 (libx264) offers the best compatibility; H.265/HEVC (libx265) achieves ~40% smaller files
- Reducing resolution (e.g. 1080p → 720p) can cut file size by ~45%
- Audio typically accounts for 10–20% of video file size — lowering bitrate saves additional space
- Supported formats: MP4, WebM, MOV, AVI, MKV, and more
- No file size limit beyond your device's available memory
- No registration, no watermarks, completely free
Frequently Asked Questions
How does the video compressor work?
Our tool uses FFmpeg compiled to WebAssembly (WASM), which runs FFmpeg's powerful video encoding engine directly inside your browser. When you click compress, your video file is read into the browser's memory and re-encoded with the H.264 or H.265 codec at the CRF value and resolution you selected. No file is ever uploaded to a server — everything happens locally on your device.
Is my video uploaded to a server?
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