Batch conversion
Add one WebM or many at once—each file exports as a separate MP4 download.
Free Online WebM to MP4
Convert WebM videos to MP4 in your browser—free, no install, no upload. Drag and drop files, export H.264 + AAC MP4 with fast-start, and download. Processing stays on your device for privacy.
Drag & drop WebM files here
or click anywhere in this area to choose files
WebM · Max 500 MB per file
Output format
All files export as MP4 (H.264 + AAC) with fast-start for wide compatibility.
Processed locally in your browser — files never leave your device. Need screen recording or faster batch export? Try the Windows desktop app.
Why Use This Free Online WebM to MP4 Converter?
Turn browser-friendly WebM clips into MP4 for editors, phones, and social apps—same privacy-first approach as our other online tools.
Wide MP4 compatibility
Output uses H.264 video and AAC audio with fast-start so MP4 files play almost everywhere.
Privacy-first
Everything runs on your device in the browser—your originals stay private.
Supported Input Formats
Convert WebM recordings and downloads to MP4 for sharing, editing, and playback.
WebM input
WebM video files up to 500 MB each.
Shorter clips process faster in the browser.
MP4 output
Export as MP4 (H.264 + AAC) with fast-start—audio is included when the source WebM has a soundtrack.
Output replaces the .webm extension with .mp4 (e.g. recording.mp4).
How to Convert WebM to MP4 Online in 3 Steps
From WebM file to compatible MP4—in minutes.
1
Add WebM files
Drag and drop WebM files or click Choose Files. Multiple files can be queued at once.
2
Convert
Click Convert to MP4 to process all queued WebM files locally in your browser.
3
Download
Save your MP4 files directly to your device when conversion completes.
More Free Video & Audio Tools
Process files instantly in your browser — 100% free, no installation, and no registration required.
WebM to MP4 FAQ
Answers to common questions about converting WebM to MP4 in your browser.
Is this online WebM to MP4 converter free?
Yes. You can convert WebM files at no cost and without creating an account. Open the page, add your files, and click Convert to MP4.
Are my files uploaded to your servers?
No. Processing runs locally in your browser. Your files are processed on your device and are not sent to Videoradius servers.
Can I convert WebM to MP4 online?
Yes. Add a WebM file and click Convert to MP4. The tool re-encodes video to H.264 and audio to AAC inside an MP4 container.
Will audio be preserved?
Yes, when your WebM includes an audio track it is converted to AAC in the MP4 output. Files without audio export as video-only MP4.
What is the maximum file size?
Each WebM can be up to 500 MB. Larger or longer files may take longer depending on your device and browser.
Need screen recording or other formats?
Use our free Online Screen Recorder to capture WebM directly, or try the Videoradius Video Converter desktop app for Windows for offline batch conversion and more formats.
Need Pro Video Tools on Windows?
Videoradius Video Converter supports 300+ formats, GPU acceleration, batch processing, and 100% offline processing.