Convert MP4 to WEBM
Convert MP4 files to WEBM locally, completely free and with maximum privacy.
Drag and drop your files here
or click to browse local files (large files supported, limited only by browser RAM)
Upload FilesPlatform Statistics
How to convert MP4 to WEBM
- Drop your .mp4 files above, or click Upload Files. You can add many files at once.
- WEBM is already selected as the output. Open the settings (gear icon) to fine-tune the result.
- Click Convert All. FFmpeg runs inside your browser through WebAssembly; nothing is uploaded.
- Download your .webm files as soon as each one finishes.
What to know about MP4 to WEBM conversion
- The video is re-encoded to VP8 video and Opus audio so it plays wherever WEBM is supported, and odd frame sizes are adjusted automatically.
- You can change the resolution, frame rate, playback speed and quality (CRF) before converting.
MP4 vs WEBM
| Feature | MP4 (MPEG-4 Part 14) | WEBM (WebM Video Container) |
|---|---|---|
| Codecs used by PureConverter | H.264 video and AAC audio | VP8 video and Opus audio |
| Best for | sharing and streaming video on any device | web video with open, royalty-free codecs |
| Opens in | every browser, phone, TV and media player | all modern browsers and VLC |
MP4 (MPEG-4 Part 14): A widely compatible digital multimedia container format, most commonly used to store video and audio.
WEBM (WebM Video Container): An open, royalty-free media file format designed for sharing video content directly on HTML5 web pages.
Conversion options
- Resolution: original, 1080p, 720p, 480p or 360p
- Frame rate and playback speed (0.5× to 2×)
- Quality presets or a custom CRF value, and lossless mode
- Audio bitrate, sample rate and channels
Frequently asked questions
Is it safe to convert MP4 to WEBM here?
Yes. Your files are processed entirely on your own device by WebAssembly code running in the browser. They are never uploaded, so nobody else can see them, and the converter keeps working even if your connection drops after the page loads.
Is there a file size limit?
There is no server-side limit. The only limit is the memory available to your browser, typically 1.5–4 GB on desktop computers.
Can I convert several MP4 files at once?
Yes. Add as many files as you like; they are converted in parallel according to your device's CPU cores, and you can apply the same settings to all of them.
Related conversions
Need the opposite? Convert WEBM to MP4.
Convert MP4 to other formats
- MP4 to MP3
- MP4 to WEBP
- MP4 to GIF
- MP4 to WAV
- MP4 to MOV
- MP4 to M4A
- MP4 to FLAC
- MP4 to MKV
- MP4 to AAC
- MP4 to OGG
- MP4 to OPUS
- MP4 to AVI
Convert other formats to WEBM
- MOV to WEBM
- MKV to WEBM
- AVI to WEBM
- WMV to WEBM
- FLV to WEBM
- M4V to WEBM
- MPEG to WEBM
- TS to WEBM
- 3GP to WEBM
- OGV to WEBM
See every MP4 converter and WEBM converter, or browse the full converter directory.