Free Video Compressor
Reduce video file sizes without sending your footage to any server. Drop in your MP4, WebM, or MOV file, pick a compression quality, and let the tool re-encode the video at a lower bitrate — all inside your browser. See the estimated compressed size before you start, monitor real-time progress, and cancel at any time. Your videos never leave your device.
Drop a video here or click to browse
MP4, WebM, MOV · Your video never leaves your device
🔒 Your videos never leave your device — all processing happens in your browser.
Frequently Asked Questions
Are my videos uploaded to a server?+
No. All compression happens directly in your browser using the MediaRecorder API. Your video files never leave your device — making this safe for personal or confidential footage.
Why does compression take as long as the video duration?+
The browser re-encodes video in real time as it plays. A 3-minute video takes approximately 3 minutes to compress. This is a limitation of browser-native video encoding, not a bug.
What video formats are supported?+
You can upload MP4, WebM, and MOV files. The compressed output downloads as a WebM file, which is compatible with all modern browsers, Google Drive, and most video editors.
Which browsers are supported?+
Chrome, Firefox, and Edge support the full feature set. Safari has limited MediaRecorder support and may not work correctly — Chrome is strongly recommended.
What do the quality presets mean?+
High targets 2 Mbps video bitrate — good for HD footage needing near-original quality. Medium targets 800 Kbps — suitable for most sharing scenarios. Low targets 300 Kbps — smallest file size with noticeable quality reduction, ideal for quick sharing.
What if the output file is larger than the original?+
This can happen if your original video was already highly compressed. Try switching to a lower quality preset, or your file is already optimal and cannot be reduced further without significant quality loss.
How Browser-Based Video Compression Works
This tool uses the browser's native MediaRecorder API to re-encode your video at a lower bitrate — entirely on your device. When you click "Compress Video", the tool plays your video internally (silent), captures the stream, and records it at the target bitrate you selected. No data is ever transmitted to any server.
Understanding Bitrate and Quality
Video file size is determined by bitrate (bits per second) multiplied by duration. A 1-minute video at 4 Mbps (typical smartphone recording) is about 30 MB. Compressing to 800 Kbps reduces the same minute to roughly 6 MB — an 80% reduction. The quality presets map to specific target bitrates: High (2 Mbps), Medium (800 Kbps), and Low (300 Kbps). The estimated output size shown before compression uses the formula (target bitrate ÷ 8 + 16 KB/s audio) × duration.
Why Real-Time Processing?
Unlike server-based tools that use FFmpeg to process video faster than real time, browser-native encoding processes frames as the video plays. A 5-minute video takes approximately 5 minutes. This is the trade-off for complete privacy — your video never leaves your device. For longer videos, keep the browser tab active during compression and use the cancel button if needed.
Output Format and Compatibility
The compressed file downloads as a WebM container (VP8 or VP9 codec with Opus audio). WebM is supported natively in Chrome, Firefox, Edge, and all Chromium-based browsers. It also plays in VLC, most modern video editors, and uploads cleanly to YouTube, Google Drive, and Slack. If you need an MP4 specifically, open the WebM in a video editor and re-export — the quality loss from the WebM→MP4 conversion is negligible.