How to Compress a Video Online Free
Large video files are a problem when you need to email a clip, upload it to a form, or share it on messaging apps. A 4K phone video can easily be 500 MB — far too large for most platforms. Browser-based video compression using FFmpeg WebAssembly lets you reduce that to under 50 MB in minutes, with no uploads to any server.
Quick Answer
Large video files are a problem when you need to email a clip, upload it to a form, or share it on messaging apps. A 4K phone video can easily be 500 MB — far too large for most platforms.
Try it now — free, no signup
Your images stay on your device. Nothing is uploaded to any server.
Step-by-Step Guide
4 steps · takes under 1 minute
Upload your video
Click or drag your MP4, MOV, AVI, WebM, or MKV video onto the tool. The file stays on your device.
Choose a quality preset
High Quality (CRF 20) keeps near-original quality with moderate reduction. Balanced (CRF 28) is the best all-round choice. Small File (CRF 35) gives maximum compression for messaging or previews.
Set a resolution limit
Leave on Original to keep the same resolution, or choose 720p, 480p, or 360p to reduce dimensions and file size further.
Download the compressed MP4
Click Compress Video. The tool re-encodes using H.264/AAC in your browser. Preview the result, then download.
Before vs After Compression
Typical result on a 1080×1080px product photo
100% Private — Zero Uploads
ImgToolkit runs entirely in your browser using the Canvas API. Your images are never sent to a server, never stored in the cloud, and never seen by anyone else. This makes it safe for sensitive documents, client work, medical imagery, and confidential screenshots.
Pro tip
Use 75–85% quality for web images — you get 60–80% smaller files with no visible difference at normal screen sizes.
Format & File Size Comparison
Same 1080×1080px photo processed four ways
| Format | Quality | File Size | Notes |
|---|---|---|---|
| PNG (original) | Perfect | 4.2 MB | No compression — too large for web |
| Compressed PNG | Visually identical | 1.1 MB | −74% — transparency preserved |
| JPG (85% quality) | Excellent | 310 KB | −93% · Best for photos |
| WebP (85%)BEST | Excellent | 205 KB | −95% · Recommended for web |
Based on a 1080×1080px photo. Results vary by image content and complexity.
Related Free Tools
All tools run in your browser — no account or upload needed
Frequently Asked Questions
2 questions answered