Audio & video converter
Convert WebM to MP4 online for free
Drop your file here
or choose a file from your device
Input: WebM · Output: MP4
Convert a WebM screen recording or web capture to an MP4 for playback on Apple devices, Windows and upload to video platforms that do not accept WebM.
About this WebM to MP4 conversion
What to select
Select a WebM video, including VP8, VP9 or AV1 sources supported by your browser, to produce a compatible H.264/AAC MP4 locally.
What you receive
Your MP4 export is encoded locally after the browser loads the media engine.
Private processing
ConvertME runs this conversion in the browser on your device. Selected files are not transferred to a processing server, and downloads are created locally after conversion.
Format details
- Input
- WebM
- Output
- MP4
- Processing
- In browser
- Cost
- Free
When to use this converter
Use this page when you need a focused WebM to MP4 conversion without installing desktop software or sending the source file to a remote conversion queue.
Practical use cases
- Convert a WebM screen recording or web capture to an MP4 for playback on Apple devices, Windows and upload to video platforms that do not accept WebM.
- Select a WebM video, including VP8, VP9 or AV1 sources supported by your browser, to produce a compatible H.264/AAC MP4 locally.
- Your MP4 export is encoded locally after the browser loads the media engine.
Best practices before downloading
- Start from the cleanest available WebM file because conversion cannot recover missing detail or corrupted data.
- Open the downloaded MP4 file before deleting the original, especially for professional or archival work.
- Use a current browser and avoid closing the tab while the local conversion engine is running.
Common issues to check
- Password-protected, corrupted or unusually large WebM files may fail in the browser.
- Metadata, embedded scripts, advanced styling or hidden document features may not be preserved in the MP4 output.
- Review the result before using it in legal, medical, financial, regulatory or production workflows.
WebM vs MP4: what changes
The converter changes the container or export format. It does not claim to improve the source file beyond what the browser can read and render.
- Source format
- WebM — WebM video (VP8/VP9/AV1), browser-native screen recording format
- Download format
- MP4 — H.264/AAC MP4, universal playback on all devices and platforms
- Conversion type
- Browser video format → Universal video
- Size impact
- MP4 output size is similar to WebM; conversion time varies by codec
- Privacy model
- Browser-based local processing with no file upload to ConvertME.
Related searches this page answers
How it works
Convert WebM in three steps
Choose a converter
Pick the exact input and output format you need.
Drop your file
Select a local file. Nothing is uploaded to our servers.
Download the result
Conversion finishes in your browser and exports locally.
FAQ
WebM to MP4 questions
How do I convert WebM to MP4?
Choose a WebM file, select Convert now and download the resulting MP4 file. Processing happens in your browser.
Is this WebM to MP4 converter private?
Yes. Your selected file is processed locally and is not uploaded to ConvertME.
Do I need an account to convert WebM files?
No. The converter is free to use without sign-up or watermarks.
What will my MP4 download contain?
Your MP4 export is encoded locally after the browser loads the media engine.