What is a .asf file?
A .asf file is an ASF video. Its registered MIME type is video/x-ms-asf, which places it in the video family of formats.
ASF stands for Advanced Streaming Format.
ASF is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
Files of this type usually begin with the bytes 30 26 B2 75. That signature is how programs recognise the format even when the extension is wrong or missing.
The same format is also saved with the extension .asx.
ASF file format details
| Extension | .asf |
|---|---|
| Format | ASF video |
| MIME type | video/x-ms-asf, application/vnd.ms-asf, video/x-ms-wm |
| Category | Video |
| Text or binary | Binary |
| File signature | 30 26 B2 75 |
| Registered with IANA | No |
| Other extensions | .asx |
How to open ASF files
| Windows | VLC media player is free and plays almost every audio and video format, ASF included in most cases. Media Player and Films and TV handle the common ones. |
|---|---|
| Mac | QuickTime Player plays formats Apple supports. VLC or IINA play most others. |
| iPhone and iPad | The Files app plays formats Apple supports. VLC for iOS plays most others. |
| Android | Most gallery and music apps play common formats; VLC for Android plays almost everything. |
Convert ASF files
TapToConvert converts ASF files in your browser, without uploading them. Open the ASF converter, or go straight to a conversion:
ASF file FAQ
What is a .asf file?
A .asf file is an ASF video, with the MIME type video/x-ms-asf.
How do I open a .asf file?
VLC media player plays most audio and video formats on Windows, Mac, iPhone and Android.
Is a .asf file safe to open?
ASF files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .asf?
video/x-ms-asf, and it is also seen as application/vnd.ms-asf or video/x-ms-wm. Web servers send this type so browsers know how to handle the file.
Is ASF a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.