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ASF MKV
File conversion

Convert ASF to MKV

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Verified by Adam B.· reviewed by FE Editorial ·updated Jul 10, 2026
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Is it possible to convert ASF to MKV?
Yes - ASF converts to MKV.

You can do it right here with our free converter - no sign-up, and your file is deleted right after.

Upload your .asf file above and download the .mkv - it is free and your file is deleted after converting. For desktop use, VLC's Convert/Save menu handles it without a terminal, and FFmpeg does it in one command. Re-encoding changes the internal codec from WMV/WMA to H.264/AAC, so expect a short wait and a minor quality trade-off compared to the source.

8 programs
Also to MKV: USM · TP · MPEG4

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Tested on macOS, Windows & Linux
Last verified Sep 2026

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ASF → MKV converterFREE
Drop a .ASF file here
or pick one - we convert it to .MKV and give you the file to download

Why convert ASF to MKV?

ASF (Advanced Systems Format) is Microsoft's aging streaming container from 1999, poorly supported outside Windows Media Player. .MKV is an open, universally supported container that carries multiple audio tracks, subtitles, and chapters, making it the preferred format for media servers like Plex, Jellyfin, and Kodi. Converting also makes the file editable in modern video editors that do not read ASF.

How to convert ASF to MKV

VLC media player FREE

Go to Media > Convert/Save, add your .asf, set the encapsulation to Matroska, and click Start.

Command line - FFmpeg CLI

Run ffmpeg -i input.asf -c:v libx264 -c:a aac output.mkv to re-encode to H.264/AAC inside an MKV container.

XMedia Recode FREE

Add your .asf, set the output container to MKV, configure the codec, and click Encode.

AviDemux OPEN-SOURCE

Open the .asf, set the output format to MKV Muxer, and save.

Programs that convert ASF

AviDemux
Free Studio
MediaCoder
Movavi Video Converter Personal
SUPER
Wondershare Video Converter
XMedia Recode
Nero Recode

About these formats

.ASF Advanced Systems Format

An ASF file is Microsoft's Advanced Systems Format container - the same format that underlies Windows Media Video (.wmv) and Windows Media Audio (.wma). On Windows, double-click it and…

Open .ASF details →
.MKV Matroska Video

An MKV file is a Matroska multimedia container that holds video, multiple audio tracks, subtitles and chapters in one file. Open it for free with VLC media player, or on Windows 11 with the…

Open .MKV details →

Quality & what to watch

  • DRM-protected ASF files cannot be converted - they produce a silent or blank output regardless of the tool used.
  • A container-only copy (FFmpeg -c copy) is fast and lossless but keeps WMV/WMA streams inside MKV, which not all players handle; re-encoding to H.264/AAC is safer for compatibility.
  • ASF and WMV share the same container format, so a .wmv file converts to MKV using exactly the same tools and steps.

Frequently asked questions

Is there quality loss when converting ASF to MKV?
With a stream copy there is no quality loss - only the container changes. Re-encoding to H.264/AAC introduces a small loss; if the source was already low-bitrate, the MKV will not look better.
Why does my converted MKV have no sound?
The WMA audio track may not have been re-encoded. In FFmpeg, add -c:a aac explicitly to force audio transcoding.
Can I convert a DRM-protected ASF file?
No - DRM-locked ASF files (such as old Windows Media store downloads) cannot be converted by any free tool and will produce a blank or silent output.
Is ASF the same as WMV?
Structurally yes - ASF and WMV use the same container format, so a file named .wmv converts to MKV using the same tools and commands.