WEBM file format (.webm)
Open VP8/Vorbis format built for the web.
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What is a WEBM file?
In short: A WEBM file (.webm) is a video file in the WEBM format. WEBM is a deliberately narrow subset of Matroska: VP8 or VP9 video with Vorbis or Opus audio, all of it free to use. It can be converted to MP4, MOV or GIF for free in a web browser with iHateFiles, without uploading it.
Announced by Google in 2010, as a royalty-free container for the web built on Matroska.
WEBM is a deliberately narrow subset of Matroska: VP8 or VP9 video with Vorbis or Opus audio, all of it free to use. It exists so browsers could ship video without patent licensing, and it is what most browser screen recorders produce.
What WEBM is good at
- Completely royalty free
- Excellent compression, particularly VP9
- Native in every browser except older Safari
Where WEBM falls short
- Poor support outside browsers: many editors and TVs refuse it
- Encoding is slower than H.264
- Files recorded in a browser often have no duration in the header
When to use WEBM
Use WEBM for video embedded in your own web pages. Convert to MP4 before sending it to anyone.
How to open a WEBM file
Chrome, Firefox, Edge and current Safari. Desktop players like VLC. Many editors and TVs will not.
| Windows | Edge and Chrome play it; VLC does too. Films & TV needs the free WebM extension. |
|---|---|
| macOS | VLC, Chrome or Firefox. QuickTime does not support it. |
| Linux | Native everywhere — WebM is the open format Linux tooling defaults to. |
| Phone | Chrome on Android plays it. iOS added WebM support in Safari 16. |
| In a browser | Every modern browser plays WebM. That is the whole point of the format. |
The thing that usually goes wrong
A browser screen recording is usually a WEBM with a broken duration, so players show it as zero seconds or refuse to seek. Converting it to MP4 rewrites the header and fixes the seeking.
Questions
What is a WEBM file?
Open VP8/Vorbis format built for the web. Files use the .webm extension.
How do I open a WEBM file?
Most video software opens WEBM directly. If yours does not, convert it here to something more common. It takes a few seconds and nothing is uploaded.
Can I convert WEBM for free?
Yes. Every conversion here is free and unlimited, because your own device does the work rather than a server we have to pay for.
Is WEBM lossless?
That depends on the codec inside the container rather than the container itself. Everything written here is re-encoded, so expect one generation of loss.