Safari compatibility converter
Convert WebM to MP4 without uploading it.
Make a WebM clip easier to play on Safari, iPhone, and apps that expect MP4. Conversion runs locally in the browser.
WebM to MP4
Creates an MP4 that works in more players.
Your selected video is processed in this browser tab. It is not uploaded to a conversion server.
Ready.
Why WebM often needs MP4
WebM can be efficient, but MP4 is still the safer format for older devices, Safari workflows, and many upload forms. This tool creates a compatible MP4 without asking you to upload the original.
If the WebM is very long, browser conversion can take time. Keep the tab open until the download is ready.
Before you start
What happens to your file?
The selected video is processed in this browser tab. It is not uploaded to a conversion server.
Best first try
Use the default settings first, then adjust resolution, quality, or clip length if the result is too large.
When this may fail
Very large files or mobile browser memory limits can stop processing.
Frequently asked questions
Does MP4 work better on iPhone?
Usually yes. H.264 MP4 is the safest choice for iOS playback and sharing.
Will the file get larger?
Sometimes. Compatibility conversion can increase file size depending on the source codec and bitrate.
Is the WebM uploaded?
No. The file is processed in browser memory and downloaded back to your device.