Does converting WMV to MKV reduce quality further?

Yes — re-encoding from one lossy format to another (WMV Video to Matroska Video) introduces a second round of compression artifacts on top of the loss already in your WMV file. The drop is usually subtle if you use a sensible quality setting, but for archival you should always keep the original WMV and avoid repeated lossy conversions.

Does the WMV to MKV conversion change my video resolution or frame rate?

No. By default we preserve the original resolution, aspect ratio, and frame rate from your WMV source. Only the container and, where required, the codec changes. If your source uses a codec that Matroska Video cannot store, the video stream is re-encoded to a compatible codec while keeping the visual properties identical.

What file size should I expect for the MKV output?

The output size depends on the content and the compression characteristics of Matroska Video. In most cases the MKV file will be in the same ballpark as your WMV input, with differences driven by how each format encodes data. There is no fixed ratio — the converter does not change quality settings unless you ask it to.

When should I convert WMV to MKV instead of staying with WMV?

Convert when the application, device, or workflow you are targeting prefers Matroska Video over WMV Video. If your current WMV file already opens and behaves correctly everywhere you need it to, there is no benefit to converting — keep the original. The most common reasons to switch are compatibility (a tool only accepts MKV), distribution (recipients expect MKV), or feature requirements specific to Matroska Video.

What is the maximum WMV file size I can convert?

MegaConvert accepts WMV files up to 100 MB on the free service, which is enough for the vast majority of real-world WMV Video files. If you have a larger file (typical for high-resolution video or uncompressed audio), please contact us — we can sometimes accommodate larger uploads for legitimate use cases.

Is my WMV file safe and private when I upload it?

Yes. Your WMV file is uploaded over HTTPS, processed in an isolated job environment, and deleted from our servers within one hour. We do not read, index, store, or share the contents of your file. No account is required, so the upload is not associated with a personal identity. See our privacy policy for the full details.

Convert WMV to MKV

Free online WMV to MKV converter. No signup required.

Drag & drop your file here

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Max file size: 100 MB

Why Convert WMV to MKV?

Understand when and why this conversion makes sense for your workflow.

Converting WMV Video to Matroska Video is often necessary to ensure playback compatibility across media players, operating systems, and streaming services. Video formats encode footage using different codecs, container structures, and compression techniques, each with distinct trade-offs between file size, quality, and support. From sharing videos online to preparing files for professional editing workflows, the right format makes a significant difference in how your content is experienced.

WMV Video has a known limitation: proprietary format with poor cross-platform compatibility. In contrast, Matroska Video offers a key advantage: supports virtually any codec and unlimited tracks for audio, subtitles, and video. While WMV Video is commonly used for legacy windows video libraries and media collections, Matroska Video is better suited for high-definition movie and tv show storage with multiple audio and subtitle tracks.

With MegaConvert, you can convert WMV to MKV online without installing software, preserving your video content accurately within the target format's specifications.

WMV vs MKV: Format Comparison

Side-by-side comparison of the source and target formats.

Property	WMV (Source)	MKV (Target)
Extension	.wmv	.mkv
Full Name	WMV Video	Matroska Video
Compression	Lossy	Lossy
File Size	Varies	Medium
Best For	Legacy Windows video libraries and media coll…	High-definition movie and TV show storage wit…
Browser Support	Limited	Wide

How to Convert WMV to MKV

Follow these simple steps to convert your file in seconds.

Upload your WMV video
Choose your .wmv file using the file picker or drag it into the upload area. Video uploads can take a few seconds for short clips and longer for high-resolution footage; the progress bar shows upload status separately from conversion. Files up to 100 MB are supported.
Start the MKV conversion
Click convert. Where the video codec is compatible with Matroska Video, the stream is repackaged without re-encoding to preserve original quality. Where re-encoding is required, we use industry-standard codec presets that balance file size against quality. Audio tracks are converted in parallel.
Wait for the video conversion to complete
Video conversions take longer than other file types because video data is much larger. A short clip might finish in 10 seconds; a 100 MB file may take a minute or two depending on whether re-encoding is required. The progress bar shows the percentage complete.
Download your .mkv file
When the conversion finishes, click the download link to save the new Matroska Video file to your computer. The file is yours — no watermarks, no expiration on the file itself, and no MegaConvert account is required to download it.

Tips for Converting WMV to MKV

Practical advice to get the best results from this conversion.

Why this conversion is worth doing

WMV Video has a known limitation: proprietary format with poor cross-platform compatibility. Matroska Video addresses this with a key advantage: supports virtually any codec and unlimited tracks for audio, subtitles, and video. Converting from WMV to MKV is most worthwhile when this specific trade-off matters for the way you intend to use the file.

Match the format to the actual workflow

WMV Video is most commonly used for legacy windows video libraries and media collections, while Matroska Video is the standard for high-definition movie and tv show storage with multiple audio and subtitle tracks. If your workflow is closer to the second pattern, converting makes sense. If you are still working in a context where WMV is the norm, converting may create unnecessary compatibility friction with collaborators or tools that expect the source format.

Watch for this limitation in the MKV output

Matroska Video has its own limitation worth understanding before you commit: not natively supported by all hardware devices and smart TVs. After the conversion completes, open the MKV file and verify that this limitation does not affect your specific use case — for some workflows it is irrelevant; for others it can be a deal-breaker.

Avoid transcoding unless necessary

Every time you transcode (re-encode) a video, some quality is lost unless you use a lossless codec. If you only need to change the container format without changing the codec, use a remux (stream copy) operation instead of a full re-encode. This preserves original quality and is much faster.

Understanding WMV and MKV Formats

Learn about the source and target file formats to understand what happens during conversion.

Source Format

WMV Video

video/x-ms-wmv

WMV (Windows Media Video) is a proprietary video compression format developed by Microsoft, based on the Advanced Systems Format (ASF) container. It was designed for streaming and local playback on Windows platforms and includes built-in DRM support for content protection. WMV has largely been superseded by H.264/MP4 for most modern use cases.

Advantages

Good compression efficiency, especially at low bitrates
Native support in Windows Media Player and Windows ecosystem
Built-in DRM support for protected content distribution

Limitations

Proprietary format with poor cross-platform compatibility
Not supported on iOS, many Android players, or web browsers without plugins
Declining usage and relevance in modern video workflows

Common Uses

Legacy Windows video libraries and media collections
DRM-protected video content from older platforms
Windows-based screen recordings and presentations

Target Format

Matroska Video

video/x-matroska

MKV (Matroska Video) is a free, open-standard multimedia container that can hold an unlimited number of video, audio, subtitle, and metadata tracks in a single file. It supports virtually any codec and is especially popular for high-definition video content with multiple audio and subtitle options. Matroska is designed to be future-proof with a flexible, extensible EBML-based structure.

Advantages

Supports virtually any codec and unlimited tracks for audio, subtitles, and video
Rich feature set including chapters, menus, metadata, and attachments
Open standard that is free and widely supported by media players

Limitations

Not natively supported by all hardware devices and smart TVs
Larger overhead compared to simpler containers like MP4
Not supported for direct playback in most web browsers

Common Uses

High-definition movie and TV show storage with multiple audio and subtitle tracks
Anime and media collections requiring multiple language options
Video archival with comprehensive metadata preservation

Frequently Asked Questions

Common questions about converting WMV to MKV.

Related Conversions

Explore other conversions related to WMV and MKV.

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Other conversions to MKV

MP4 to MKV AVI to MKV MOV to MKV FLV to MKV WEBM to MKV M4V to MKV MPG to MKV MPEG to MKV 3GP to MKV OGV to MKV

Convert WMV to MKV

Why Convert WMV to MKV?

WMV vs MKV: Format Comparison

How to Convert WMV to MKV

Upload your WMV video

Start the MKV conversion

Wait for the video conversion to complete

Download your .mkv file

Tips for Converting WMV to MKV

Why this conversion is worth doing

Match the format to the actual workflow

Watch for this limitation in the MKV output

Avoid transcoding unless necessary

Understanding WMV and MKV Formats

WMV Video

Advantages

Limitations

Common Uses

Matroska Video

Advantages

Limitations

Common Uses

Frequently Asked Questions

Does converting WMV to MKV reduce quality further?

Does the WMV to MKV conversion change my video resolution or frame rate?

What file size should I expect for the MKV output?

When should I convert WMV to MKV instead of staying with WMV?

What is the maximum WMV file size I can convert?

Is my WMV file safe and private when I upload it?

Related Conversions

Other conversions from WMV

Other conversions to MKV