ASX Video — A .asx file is a ASX Video. It is a video format used to store movies and animation, typically with video and audio tracks.
Quick facts
What is .asx
A .asx file is a ASX Video. It is a video format used to store movies and animation, typically with video and audio tracks.
In the mime-db registry it maps to video/x-ms-asf. When serving .asx over HTTP, set the Content-Type header as shown in Developer info below.
Related entities: it maps to video/x-ms-asf — and is delivered over HTTP via the Content-Type header.
How to open .asx files
Developer info
When served over HTTP, responses should set the following header:
Content-Type: video/x-ms-asf
Common software that reads/writes .asx:
Relation chain
Related extensions
Related MIME types
Common uses
How to edit .asx files
How to create .asx files
Frequently asked questions
Common options include VLC, MPV, HandBrake. 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 .asx extension.
video/x-ms-asf is the media type identifier used for .asx files during network transfer (for example in the HTTP Content-Type header).
Sources & standards
Updated 2026-08-18
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