Free Video Compressor — Reduce File Size Online
Compress videos with H.264 encoding right in your browser — a free alternative to HandBrake. No sign-up, no uploads.
Shrink video file size with quality presets — small, medium, large, or custom CRF — while preserving visible quality. Works on MP4, MOV, MKV, WebM, and AVI inputs, all in your browser via ffmpeg.wasm. No upload, no account, no watermark. A free alternative to HandBrake when you don't want a desktop install, and to Adobe Media Encoder for casual compression.
Built and maintained by James Nicolaus
Quality Presets
Choose Small File, Balanced, or High Quality — or set a custom CRF value for precise control over the quality/size trade-off.
Resolution Control
Optionally downscale to 1080p, 720p, 480p, or 360p while maintaining aspect ratio. Great for cutting file size further.
H.264 + AAC Output
Output is MP4 with H.264 video and AAC audio — the most universally compatible format for web, mobile, and social media.
100% Private
All processing happens in your browser using WebAssembly. Your video never leaves your device — no uploads, no servers.
Free Video Compressor — Reduce Video Size Online
The Free Video Compressor lets you reduce video file size directly in your browser using H.264 (libx264) encoding via WebAssembly. Choose a quality preset or fine-tune with custom CRF and resolution settings. Your video never leaves your device — no uploads, no sign-up, no file size limits.
Need to switch container or codec instead of just shrinking? The free video converter handles format swaps. Cropping out the boring intro before compressing is the easiest way to shave megabytes — the free video trimmer does that with stream copy and zero quality loss.
Features
- Quality presets — Small File, Balanced, High Quality, or Custom. Each preset configures CRF and resolution for the best results.
- CRF control — Fine-tune the quality/size trade-off with a slider from 0 (lossless) to 51 (maximum compression).
- Resolution downscaling — Reduce from 4K to 1080p, 720p, 480p, or 360p while maintaining aspect ratio.
- Audio passthrough — Copy the audio stream without re-encoding for faster processing, or re-encode to AAC 128k.
- MP4 output — H.264 + AAC with faststart flag for instant web playback. Compatible with every device and platform.
- 100% client-side — Uses ffmpeg.wasm (WebAssembly). Your video never leaves your device.
How to Compress a Video
- 1. Add a video — Drag and drop a video file or click to browse. Supports MP4, WebM, MOV, AVI, MKV.
- 2. Choose a preset — Select Small File for maximum compression, Balanced for a good trade-off, or High Quality for minimal loss.
- 3. Adjust settings — Optionally tweak CRF, resolution, and audio settings for precise control.
- 4. Compress — Click Compress and wait. The progress bar shows real-time status. Video encoding is CPU-intensive and may take a few minutes.
- 5. Download — When complete, see the before/after file size and click Download.
Video Compressor Comparison
| Feature | Free Tool Shed | HandBrake | Online Tools |
|---|---|---|---|
| Price | Free | Free | Free (limited) or $5-15/mo |
| Installation | None (browser) | Desktop app install | None |
| Privacy | Local processing only | Local processing | Files uploaded to server |
| Speed | Slower (single-thread WASM) | Fast (native, multi-thread) | Varies (server-side) |
| File size limit | ~500 MB-1 GB (browser RAM) | No limit | 25-500 MB typically |
| Sign-up required | No | No | Usually yes |
Tips, Mistakes & Takeaways
Tips
- →Start with the 'medium' preset — targets roughly 50% size reduction with negligible visible quality loss on most footage.
- →Custom CRF: 18 is visually lossless, 23 is the default, 28+ shows compression artifacts on motion-heavy footage.
- →For Slack or Discord uploads, target 8 MB and let the encoder pick the CRF accordingly.
- →Compress to MP4 (H.264) for maximum compatibility; WebM (VP9/AV1) for smaller files when the destination accepts it.
Common Mistakes
- !Compressing an already heavily-compressed source — additional compression stacks artifacts. Start from the highest-quality master you have.
- !Picking a preset much smaller than the source resolution warrants — 4K → 480p loses detail you can't recover later.
- !Walking away from the tab during encoding — most browsers throttle background tabs and encoding slows dramatically.
Key Takeaways
- ✓Quality-targeted compression via CRF or preset, in-browser, with no upload.
- ✓ffmpeg.wasm is slower than native ffmpeg but produces bit-identical output for the same settings.
- ✓Focused on the formats people actually share — not a transcoder for every esoteric codec.
Frequently Asked Questions
When should I use this vs. HandBrake?
Use this tool for quick, one-off compressions when you don't want to install software — especially on Chromebooks or work machines. Use HandBrake for long videos, batch processing, or when you need maximum encoding speed.
What CRF should I use?
CRF 18-20 is visually lossless for most content. CRF 23-26 is a good balance of quality and size. CRF 28-32 produces noticeably softer video but much smaller files — fine for low-motion content like presentations or screen recordings.
Can I compress a 4K video to 1080p?
Yes. Set the Max Resolution to 1080p and the video will be downscaled while maintaining aspect ratio. Combined with CRF compression, this can reduce a 4K video to 10-20% of its original size.