Select File
or drag and drop files here
How to Compress a Video
Upload a video file (MP4, WebM, MOV, AVI, or MKV)
Choose output width to scale down resolution — the biggest factor in file size reduction
Select quality level — Medium is the best balance for most use cases
Click Process and download your compressed MP4
Choosing the right settings for your use case
- Email attachments: 640px width, Low quality. Target under 10MB for most email clients.
- Social media upload (Instagram, TikTok, YouTube): 854px or 1280px, Medium quality. Platforms re-encode anyway.
- WhatsApp and messaging: 640px, Medium quality. Target under 16MB for WhatsApp's limit.
- Archiving with smaller size: Original resolution, Medium quality. Preserves dimensions while reducing bitrate.
- Preview or thumbnail video: 426px, Low quality. Tiny file size for quick loading.
Why resolution matters more than quality level
Video file size scales with the square of resolution. Halving the width (e.g. 1080p to 540p) reduces pixel count by 75%, which directly reduces the encoded bitrate and file size — regardless of quality setting. Quality level adjusts the bitrate for a given resolution. For maximum compression, reduce resolution first, then quality. For best visual results at a smaller size, reduce resolution only.
Key Features
Hardware-Accelerated Encoding
Uses the WebCodecs API for GPU-assisted video encoding, significantly faster than FFmpeg WebAssembly alternatives.
MP4 Output
Always outputs a clean MP4 file compatible with all devices, platforms, and video hosts.
Resolution Scaling
Scale video width down to 1280px, 854px, 640px, or 426px. Height is adjusted automatically to preserve aspect ratio.
No Upload Required
All processing happens in your browser. Files never leave your device.
Complete Privacy
Video files are processed entirely in your browser using the WebCodecs API. No data is uploaded to any server at any point.
Frequently Asked Questions
How much will compression reduce my file size?
It depends on the source. Scaling from 1080p to 640px typically reduces file size by 70-85%. Quality level has a smaller impact — switching from High to Low reduces size by roughly 30-40% with visible quality loss.
What is the difference between quality levels?
High preserves detail and is suitable for archiving or professional use. Medium is the best balance for sharing and uploading. Low produces the smallest files but with noticeable quality reduction, suitable for previews or thumbnails.
Is there a file size limit?
The tool enforces a 500MB limit. Mediabunny streams files efficiently so memory usage stays low even for large inputs.
Which browsers are supported?
Chrome 94+ and Edge 94+ are fully supported. Firefox has partial WebCodecs support. Chrome is recommended for best performance.