WebM to MP4
Turn WebM screen recordings and downloads into MP4 videos that play on any phone, computer or TV.
or drop it here · up to 50 MB, free
Bigger files? Pro converts files up to 500 MBOver the free limits: you can unlock the download from €1.99.
Working on it…
Your file is ready
Free · No sign-up · No watermark · Your files never leave your device
WebM to MP4 in 3 steps
- Select your WebM video, or drop it on the box.
- Click Convert to MP4.
- Download the MP4 when the progress bar is full.
Why WebM videos need converting
WebM is the format browsers use for screen recordings, web animations and many downloaded clips. It plays in Chrome and Firefox, but iPhones, PowerPoint, many video editors and smart TVs either refuse it or play it without sound. MP4 with H.264 video and AAC sound is the format all of them accept.
The video inside a WebM file is VP8, VP9 or AV1, which MP4 players do not expect, so the tool re-encodes it as H.264 at high quality, frame by frame, in your browser. The sound, usually Opus, becomes AAC in Chrome, Edge and Safari; Firefox cannot create AAC, so there it stays Opus, which some older players and TVs skip. The picture keeps its resolution and frame rate, and the conversion takes about as long as the video, often less on a recent computer.
Frequently asked questions
How do I convert WebM to MP4 for free?
Select the WebM file and click Convert to MP4. The progress bar shows how far the conversion is, and the MP4 downloads when it is finished. There is no sign-up, no watermark and no length limit beyond the file size.
Will the MP4 play on my iPhone?
Yes, when you convert in Chrome, Edge or Safari: the video becomes H.264 and the sound AAC, the combination iPhones, Macs, Windows, Android, PowerPoint and smart TVs all play. Firefox cannot create AAC, so there the sound is Opus, which some players and devices do not play.
Does the conversion reduce quality?
The video has to be re-encoded, but it is done at a high bitrate and the same resolution and frame rate, so the difference is very hard to see. If the MP4 turns out too big, run it through Compress Video afterwards.
How long does it take?
Roughly as long as the video plays, often less on a recent computer, because each frame is decoded and encoded again on your device. Short screen recordings take a few seconds. Keep the tab open until the download starts.
Which browsers can do this?
Converting uses the video encoder built into your browser. Chrome and Edge on a computer or Android phone work best. Safari 17 or later and recent Firefox versions also work, but they are slower with large videos. If your browser cannot do it, the page tells you before you start.
Is my video uploaded to a server?
No. The video is processed by your own browser on your device, so it is never sent to us or stored anywhere. That also means there is no upload to wait for, which saves a lot of time with large videos.