WebM to MP4 Converter

Convert WebM videos to MP4 instantly and privately. Everything happens on your own device — nothing is uploaded to a server.

Drop your WebM file here

Accepted: .webm · Max 300MB

Choose File

Files stay on your device — nothing is uploaded.

The video engine downloads once (about 30MB) the first time you convert, then stays cached in your browser for future conversions. Video encoding is CPU-intensive, so longer or higher-resolution clips take noticeably longer than audio extraction.

What is WebM to MP4 conversion?

WebM to MP4 conversion re-encodes your video's picture and sound into MPEG-4 Part 14, changing the container and codecs while keeping the same content. WebM is an open, royalty-free video container developed for the web, typically pairing VP8/VP9 video with Vorbis or Opus audio. It's built into every modern browser and favored for its smaller file sizes. MP4 is the most widely supported video container format, typically pairing H.264 video with AAC audio. It's the default format for video recorded on phones and shared online.

How to convert WebM to MP4

Choose a WebM file using the drop zone above (or drag and drop it in).
Wait a moment while your browser converts the file locally.
Click "Download" to save your new MP4 file.

Why convert WebM to MP4?

Converting between video formats is useful when a platform, editor, or device only accepts MP4, or when you want MP4's balance of compatibility and file size instead of WebM's.

WebM vs MP4

Property	WebM	MP4
Compression	Lossy	Lossy
Typical use	Embedded video on websites	Phone and camera video recordings

Is this conversion private?

Yes. This WebM to MP4 converter runs entirely in your browser using a WebAssembly build of FFmpeg — your file is never uploaded to our servers, stored, or logged. Closing this tab discards everything.

Supported browsers

This converter works in all modern browsers, including Chrome, Firefox, Safari, and Edge, on both desktop and mobile (Android and iOS).

Frequently Asked Questions

How do I convert WEBM to MP4?: Choose a WEBM file using the drop zone or "Choose File" button above. The converter runs in your browser using a WebAssembly build of FFmpeg and gives you a "Download" button for the resulting MP4 file — no upload, no waiting on a server.
Is this WEBM to MP4 converter free?: Yes. The converter is completely free with no sign-up, no watermark, and no limit on how many files you convert.
Are my files uploaded to a server?: No. This conversion happens entirely inside your browser using a WebAssembly build of FFmpeg. Your file is never uploaded, stored, or transmitted anywhere.
Does converting WEBM to MP4 reduce quality?: Re-encoding between video formats involves recompressing both picture and sound, so there's a small quality trade-off — but the default settings here stay close to the source while keeping in-browser conversion practical.
Can I use this converter on my phone?: Yes, but audio/video conversion is CPU-intensive. It will work on modern phones, though larger files may take noticeably longer than on desktop.
What is the maximum file size I can convert?: Because conversion happens on your own device, the limit depends on your browser and device memory. We recommend keeping individual files under 300MB, and a few minutes long, for the smoothest experience.

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What is WebM to MP4 conversion?

Property

WebM

MP4

Compression

Lossy

Typical use

Embedded video on websites

Phone and camera video recordings

Frequently Asked Questions

How do I convert WEBM to MP4?

Choose a WEBM file using the drop zone or "Choose File" button above. The converter runs in your browser using a WebAssembly build of FFmpeg and gives you a "Download" button for the resulting MP4 file — no upload, no waiting on a server.

Is this WEBM to MP4 converter free?

Yes. The converter is completely free with no sign-up, no watermark, and no limit on how many files you convert.

Are my files uploaded to a server?

No. This conversion happens entirely inside your browser using a WebAssembly build of FFmpeg. Your file is never uploaded, stored, or transmitted anywhere.

Does converting WEBM to MP4 reduce quality?

Re-encoding between video formats involves recompressing both picture and sound, so there's a small quality trade-off — but the default settings here stay close to the source while keeping in-browser conversion practical.

Can I use this converter on my phone?

Yes, but audio/video conversion is CPU-intensive. It will work on modern phones, though larger files may take noticeably longer than on desktop.

What is the maximum file size I can convert?

Because conversion happens on your own device, the limit depends on your browser and device memory. We recommend keeping individual files under 300MB, and a few minutes long, for the smoothest experience.