Is this WMV to MKV converter really free?

Yes. Up to 5 files at a time, no signup, no catch. The free tier adds a small watermark to image output — Pro ($9.99/mo or $49/yr) removes it, raises the file size limit to 500 MB, and unlocks unlimited batch conversion.

Are my files uploaded to a server?

No — and you can verify it yourself. Open DevTools → Network tab, then convert a file. You'll see zero upload requests. Everything runs right in your browser. We never see your files.

How long does conversion take?

Usually 1–3 seconds for a typical file. The very first conversion on a fresh page load may take 5–20 seconds while the converter engine loads — after that it's instant. Your CPU does all the work locally.

What is the file size limit?

Free: up to 10 MB per file, 5 files per batch. Pro: up to 500 MB per file, unlimited batch. If you're working with large videos or RAW photos, Pro is built for that.

Can I batch convert multiple WMV files at once?

Yes — drop multiple files at once (or Ctrl/Cmd+click to select them) and they all convert in parallel. Free accounts handle up to 5 files per batch; Pro has no limit.

How large can my video files be?

Free accounts support files up to 10 MB — enough for short clips and GIFs. Pro raises that to 500 MB, which covers most 1080p videos. For files over 1 GB, a native app like HandBrake will be faster.

Will the video lose quality during conversion?

When only the container changes (e.g., MKV → MP4 where both use H.264), there's zero quality loss — it's a lossless rewrap. When the codec changes, we encode at CRF 23, which is near-transparent for most content.

Does WMV to MKV conversion improve video quality?

No — re-encoding re-compresses the video, which can reduce quality. For archival, re-encode at high bitrate (10+ Mbps for HD). The benefit is compatibility: MKV plays everywhere WMV doesn't.

After converting WMV to MKV, will Plex detect the video metadata correctly?

Yes — Plex's metadata matching works on the filename, not the container. Rename the MKV using the movie or show name and year (e.g., 'The Matrix (1999).mkv') and Plex will match it automatically.

How private is this converter?

Completely private — by design, not policy. There is no upload endpoint. Files are processed right inside your browser tab and disappear the moment you close it. We collect only anonymous page-view counts; your file content is never seen or stored.

WMV to MKV Converter — Free, Online, No Upload

How to convert WMV to MKV online

1
Drop your WMV file
Drag and drop your Windows Media Video file onto the converter, or click to browse your files. You can select up to 5 at once. Nothing leaves your device — conversion happens right here in the browser.
2
Hit Convert — it happens locally
Click Convert and watch it go. There's no upload, no server queue, no waiting. The converter runs Windows Media Video → Matroska Video entirely in your browser tab. Most files finish in 1–3 seconds.
3
Download your MKV
Your Matroska Video file is ready. Click Download, or grab a ZIP if you converted a batch. Close the tab and everything disappears — no copies kept anywhere.

WMV vs MKV: format overview

WMV

Windows Media Video

Microsoft · 2003

Compression: lossy
Transparency: No

✓ Good compression for Windows-native workflows
✓ DRM support for content protection
✗ Not supported on macOS, iOS, Android natively

MKV

Matroska Video

Matroska.org · 2002

Compression: lossy
Transparency: No

✓ Supports virtually any codec combination
✓ Multiple audio tracks and subtitles per file

WMV magic bytes: 30 26 B2 75 8E 66 CF 11

MKV magic bytes: 1A 45 DF A3

Why convert WMV to MKV?

WMV is a closed, proprietary format that requires Windows Media codecs to decode — codecs that are not available on Linux, are absent from most open-source tools, and are increasingly dropped from modern software. If you run Plex, Jellyfin, Kodi, or any Linux-based media server, WMV files are second-class citizens that may not transcode cleanly or may force your server to work harder than necessary.

MKV (Matroska) is the container format that open-source media servers were built around. Plex, Jellyfin, Kodi, and VLC all treat MKV as a first-class format. MKV supports multiple audio tracks, subtitle streams, chapter markers, and HDR metadata — capabilities that WMV lacks entirely. It is the standard container for Blu-ray rips and high-quality digital media collections.

Converting WMV to MKV gives your video a future-proof container that integrates cleanly with your media server. The video and audio are re-encoded to open codecs — typically H.264 or H.265 for video and AAC for audio — which any media server can handle without transcoding overhead. The resulting MKV file is better indexed, more compatible, and better supported than WMV across every modern media platform. File sizes may be smaller than the original WMV at equivalent quality, depending on the codec used.

Quality & file size: WMV to MKV

Typical file sizes: WMV 50–150 MB → MKV 200–800 MB.

Both WMV and MKV use lossy compression. We transcode at high quality settings (equivalent to MKV's recommended web quality) to minimize generational loss.

Color depth: WMV supports standard color, MKV supports standard color.

Transparency: WMV does not support transparency. MKV does not support transparency — transparent areas become solid white.

Frequently asked questions

Privacy: how FormatDrop handles your files

Your WMVfiles are converted 100% inside your browser. They are never uploaded to our servers, never stored, and never seen by anyone other than you. This isn't a privacy policy claim — it's an architectural guarantee: our server has no endpoint that receives file bytes.