Convert WMV to MKV — Free & Private
WMV (Windows Media Video) files were the default output of Windows Movie Maker, Microsoft Expression Encoder, and early screen-recording tools. Corporate training libraries, 2000s home movies, and screen captures from older Windows machines are commonly stored as WMV. Modern browsers, Mac, iOS, and Android all lack native WMV support, making conversion essential before sharing or archiving these files. Converting to MKV gives you the most flexible open-source container — able to preserve H.264 or H.265 video with multiple subtitle tracks, chapter markers, and metadata. Ideal for media libraries managed by Plex, Kodi, Emby, or VLC.
How to Convert WMV to MKV
Click "Convert Now" to open with WMV → MKV pre-selected.
Drag & drop your WMV file or click Browse.
FFmpeg.wasm processes your video locally — nothing uploaded.
Your converted MKV file downloads automatically.
Why Convert WMV to MKV?
- 🖥️ From WMV — convert Windows Media Video to formats with broader cross-platform support
- 📦 Flexible container — supports multiple audio tracks, subtitles, and chapters
- ✨ Quality preserved — video copied without re-encoding where possible
- 🌍 Open standard — supported by VLC, Plex, Kodi, and most players
- 🔊 Multi-track audio — store multiple language tracks in one file
- 🔒 100% private — files never leave your device
WMV vs MKV — Format Comparison
Features
100% Private
Files never leave your browser.
Instant
In-browser processing, no waiting.
Free
No account, no fee, no watermarks.
Quality Preserved
High-quality settings by default.
Mobile-Friendly
Works on any device.
No Install
Works in any modern browser.
Key Questions About WMV to MKV, Answered
Direct answers structured for AI extraction, voice search, and featured snippets.
Will my video be re-encoded or just remuxed when converting WMV to MKV?
Usually a remux. Matroska's flexible container has a codec slot for VC-1, the codec inside WMV, so Convertlo can typically repackage the existing video and audio streams into an MKV wrapper without re-encoding.
- VC-1-in-WMV → MKV: remuxed, instant, zero quality loss
- Audio (WMA) carries over, though some players read WMA-in-MKV better than others
- Remuxing won't fix device playback issues — only re-encoding to H.264 will
Does converting WMV to MKV re-encode the video, or just change the container?
Standard WMV (VC-1 codec) can be remuxed directly into MKV without re-encoding — the same VC-1 stream is wrapped in the new container, so quality is unchanged. VLC, Plex, and Kodi all decode VC-1 inside MKV natively.
- VC-1 WMV → MKV: remux (no re-encode) — identical quality, just a different wrapper
- VLC, Plex, Jellyfin, Kodi: all play VC-1 inside MKV without any extra codec setup
- iPhone, Android, and browsers: VC-1 is not supported even inside MKV — use MP4 (H.264) for those devices
How much will the file size change going from WMV to MKV?
Since the conversion is typically a remux, the file size stays essentially the same — only the container wrapper changes, not the actual video or audio data.
- VC-1-in-WMV → MKV: size unchanged (remux)
- Any size difference comes from minor container overhead, not re-encoding
- To actually shrink the file, re-encode to H.265 or VP9 rather than just changing the container
Why does my old WMV file stop playing on modern devices?
WMV relies on Microsoft's VC-1 codec, which Windows supports natively but which iOS, macOS, and most Android devices never adopted without an extra codec pack. Remuxing into MKV doesn't change the underlying codec, so the same playback gaps remain on phones and browsers — though MKV opens reliably in VLC, Plex, Jellyfin, and Kodi.
- iPhone, iPad, and most Android phones: no native WMV or MKV playback
- VLC, Plex, Jellyfin, Kodi: open the MKV and its VC-1 video without issue
- For playback on phones and browsers, re-encoding to MP4 (H.264) is the fix
Go Deeper: WMV to MKV Resources
In-depth articles to help you understand the formats, pick the right settings, and get the best results.