Free Video Compressor
100% Private · No Uploads · No Watermark · No Account
Reduce MP4, MOV, and WebM file size directly in your browser. Pick a quality preset and optional resolution cap — FFmpeg WebAssembly does the rest. Your video never leaves your device.
Who Uses This Tool?
Email & Messaging
Most email clients cap attachments at 25 MB and messaging apps have similar limits. Compress a recording to slip it under the threshold without sharing a link.
Social Media Upload
Instagram, TikTok, and LinkedIn all apply their own compression on upload. Pre-compressing at 720p / Medium gives you control over quality instead of letting the platform decide.
Website & App Backgrounds
Loop videos used as hero backgrounds should be under 5 MB. Drop a 4K recording to 480p at Small quality and slash load time without losing perceived quality at that size.
Cloud Storage & Backup
Compress archival recordings, lectures, or screen captures before uploading to Google Drive or Dropbox to stay within free storage quotas.
How SimpleTool Compares
| Feature | SimpleTool | Desktop App | Online Service |
|---|---|---|---|
| Video stays on your device | ✅ | ✅ | ❌ |
| Free with no watermark | ✅ | ❌ (paid) | ⚠️ Limited free tier |
| No account required | ✅ | ✅ | ❌ |
| Works in the browser | ✅ | ❌ | ✅ |
| H.264 output (universal) | ✅ | ✅ | ⚠️ Varies |
| Quality + resolution control | ✅ | ✅ | ⚠️ Sometimes |
| No file size limit | ✅ | ✅ | ❌ |
Tips for Smaller Files
Lower the resolution first
Halving the height (e.g. 1080p → 720p) reduces the pixel count by 56% — the biggest single lever for file size. Use this before lowering quality.
Start with Medium quality
Medium (CRF 28) is the sweet spot for most content. The quality difference from High is barely visible at normal viewing sizes, but the size savings are substantial.
Already-compressed videos won't shrink much
Videos downloaded from YouTube, Netflix, or social platforms are already aggressively compressed. Re-encoding them rarely saves space — it may even increase the file size.
Screen recordings compress extremely well
Desktop screen recordings have large static areas that H.264 compresses very efficiently. A 200 MB screen recording can often compress to under 20 MB at Medium quality.
Limitations
- Requires SharedArrayBuffer — works in Chrome, Edge, and Firefox. Safari on macOS works; very old Safari on iOS may not.
- The FFmpeg encoder (~20 MB) is downloaded from a CDN on first use and cached locally.
- Compression is single-threaded in WASM — long 4K videos may take several minutes.
- Output format is always MP4 (H.264 + AAC). WebM or other formats are not supported.
- Very large files (>2 GB) may run into browser memory limits on devices with under 8 GB RAM.
Frequently Asked Questions
Does my video get uploaded to a server?
No. FFmpeg runs as a WebAssembly module entirely inside your browser tab. Your video bytes never leave your device — there is no server involved at any point.
Why is my compressed file larger than the original?
This happens when the source video is already heavily compressed (e.g. downloaded from a streaming service or already exported at a low bitrate). Re-encoding through H.264 at those settings adds container overhead without removing more data. Try a lower quality setting (Small), or accept that the source is already near its minimum size.
What video formats are supported?
Input: MP4, MOV (QuickTime), WebM, AVI, and MKV. The output is always an MP4 file encoded with H.264 video and AAC audio — the most universally compatible format for sharing and uploading.
How long does compression take?
It depends on the video length, resolution, and your device. A 1-minute 1080p clip typically takes 1–3 minutes on a modern laptop. The first run also downloads the FFmpeg encoder (~20 MB) from a CDN, which is then cached so subsequent runs start immediately.
What does the resolution cap do?
It limits the maximum height of the output video. For example, 720p means the output will be no taller than 720 pixels — a 4K video becomes 720p, but a 480p video is unchanged (it never upscales). Lowering resolution is one of the most effective ways to reduce file size.
What quality setting should I choose?
Medium is the best starting point for most videos — it produces a noticeable size reduction with minimal visible quality loss. Use High if you need to preserve fine detail (screencasts, text-heavy content). Use Small for social media previews, email attachments, or situations where file size matters more than pixel perfection.
Is this really free with no watermarks?
Yes. The compression runs locally using FFmpeg WebAssembly — there are no server costs and nothing to monetise, so there are no watermarks, no daily limits, and no account required.
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