Free Online Video Compressor - 100% Private & Secure

Open VideoSOS

Navigate to videosos.io in any modern web browser. VideoSOS works best on:

Chrome 57+ (Recommended for best performance)
Firefox 52+
Safari 11+
Edge 16+

💡First-time setup: The first time you load VideoSOS, it will download the FFmpeg WebAssembly library (about 25MB). This only happens once and enables offline compression afterwards.

Select Your Video

Click the upload area or drag and drop your video file directly onto the page. VideoSOS supports all major video formats:

Common Formats

• MP4 (H.264, H.265)
• MOV (Apple QuickTime)
• AVI (Audio Video Interleave)
• WebM (VP8, VP9)

Additional Formats

• MKV (Matroska)
• FLV (Flash Video)
• WMV (Windows Media)
• M4V, 3GP, and more

⚠️File size limits: Desktop computers can typically handle files up to 2GB. On mobile devices, we recommend keeping files under 500MB for optimal performance.

🔒Privacy guarantee: Your video file never leaves your device. VideoSOS processes everything locally in your browser using WebAssembly technology.

Choose Compression Settings

Select the quality level and output format that best matches your needs:

Quality Presets

High Quality

Best for archiving or professional use. Minimal quality loss, moderate file size reduction (30-50%).

Medium Quality (Recommended)

Balanced compression. Great for general use, social media, and sharing. Reduces file size by 60-70%.

Low Quality

Maximum compression for email attachments or quick sharing. Reduces file size by 80%+ with visible quality trade-offs.

Output Format

MP4Universal compatibility. Best for most use cases including social media, web, and mobile devices.
WebMOptimized for web streaming. Excellent compression with modern browsers support.
AVILegacy format for compatibility with older software and systems.

Start Compression

Click the "Compress Video" button to start processing. You'll see:

Progress bar: Real-time compression progress from 0% to 100%
Time estimate: Approximate time remaining based on file size and your device's performance
Compression ratio: How much smaller your video is becoming

Processing time: Compression speed depends on your video length, resolution, chosen quality settings, and your device's CPU. A 10-minute 1080p video typically takes 2-5 minutes on modern hardware.

Download Your Compressed Video

Once compression completes, click the "Download" button to save your compressed video. The file will be saved to your default downloads folder.

After Download:

Compare the file sizes to see your compression savings
Play the video to verify quality meets your expectations
Process another video or adjust settings and try again

🎉Congratulations! You've successfully compressed your first video with VideoSOS. Your original file remains unchanged, and no data was sent to any server.

Best Practices & Tips

⚡Performance Tips

• Close unnecessary browser tabs to free up memory
• Use Chrome for fastest compression speed
• Ensure your device is plugged in for longer videos
• Don't switch tabs during compression for best performance

🎯Quality Tips

• Start with Medium Quality preset for best results
• Always compare output with original before deleting
• For social media, Low Quality is often sufficient
• Use High Quality for videos you plan to edit later

Next Steps

Now that you know the basics, explore these guides to become a VideoSOS power user:

Getting Started with VideoSOS

What You'll Learn