🎬 MP4 to WebM
Convert MP4 to WebM — Free & Private
Transform MP4 videos to WebM format for web publishing. WebM is the open-source format supported natively by all modern browsers.
✓ Free forever✓ No upload✓ No signup✓ Instant
Ready to convert your MP4 to WebM?
100% in your browser · FFmpeg-powered · Instant download
How to Convert MP4 to WebM
1
Open the Converter
Click "Convert Now" — opens on the Video tab with MP4 → WebM pre-selected.
2
Upload Your MP4
Drag & drop your video file or click Browse. Up to 500 MB supported.
3
Convert Instantly
FFmpeg runs entirely in your browser — no server upload needed.
4
Download WebM
Your converted file downloads automatically, ready to use.
Why Convert MP4 to WebM?
- 🎬 WebM is the ideal format for embedding video on websites — smaller and browser-native
- 💾 Open-source format — no licensing issues, supported by Chrome, Firefox, and Edge
- 📦 Batch support — convert multiple files at once with Batch Convert mode
- 🔐 100% private — files stay on your device, never uploaded to any server
- 🆓 Free forever — no watermarks, no limits, no credit card
- ⚡ Instant — FFmpeg WebAssembly runs directly in your browser
Features
100% Private
Files never leave your browser. Zero server uploads.
FFmpeg-Powered
Industry-standard FFmpeg runs as WebAssembly in your browser.
Free
No account, no fee, no watermarks. Ever.
Batch Convert
Convert multiple MP4 files to WebM in one go.
High Quality
Output quality matches the original source video.
Mobile-Friendly
Works on any device — phone, tablet, desktop.
Frequently Asked Questions
Yes, completely free with no limits or watermarks. Convertlo runs entirely in your browser.
No. All conversion happens locally in your browser using FFmpeg compiled to WebAssembly. Your files never leave your device.
Yes. The conversion preserves video quality at a high bitrate setting. Output quality depends on the original file quality.
WebM is the ideal format for embedding video on websites — smaller and browser-native
Yes — enable Batch Convert mode to process multiple MP4 files at once, each producing its own WebM output.