How to use the WebM to MP4
- Add your .webm video.
- MP4 is preselected. Choose High, Balanced or Small file.
- Press “Convert” and download the MP4.
Why convert WebM to MP4
WebM (VP8/VP9) is great for the web but poorly supported by iPhones, older Windows players, PowerPoint and many editing apps. MP4 with H.264 video is the most compatible format there is.
Quality and file size
- High: visually the same as the original, larger file.
- Balanced: recommended for sharing and uploading.
- Small file: smallest size for messaging apps.
How the converter works
Conversion runs in your browser with FFmpeg (WebAssembly), so your file is not uploaded. The first conversion downloads the converter engine (about 30 MB) once; files up to 500 MB are supported.
Frequently asked questions
Is there a watermark or time limit?
No watermark and no time limit. Files up to 500 MB are supported.
Can I convert WebM to MP4 on iPhone?
Yes, in Safari on iOS. Long videos are faster to convert on a computer.
Can I extract only the audio?
Yes. Choose MP3 as the output format to get the sound only.