WebM Video — Royalty-free web video container with VP9/AV1 codecs.
Quick facts
What is .webm
A .webm file is a WebM Video — Royalty-free web video container with VP9/AV1 codecs.
In the mime-db registry it maps to video/webm, and it is marked as non-compressible. When serving .webm over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to video/webm — and is delivered over HTTP via the Content-Type header.
How to open .webm files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: video/webm
Common software that reads/writes .webm:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .webm files
How to create .webm files
Frequently asked questions
Common options include Chrome, VLC, Firefox. You can also open many of these files with built-in viewers or a browser.
Create a new file in any text editor or the app that owns the format and save it with the .webm extension.
video/webm is the media type identifier used for .webm files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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