WTV to Y4M Converter
Processing entirely on your device — large files may take a moment.
Convert Y4M raw video to MP4/WEBM with real compression. If your files are still in WTV format, this page is the shortcut: WTV is Windows Media Center's TV recording format — tuner captures with metadata, subtitles and multiple audio tracks inside.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How WTV compares to Y4M
| WTV | Y4M | |
|---|---|---|
| Structure | Microsoft WTV container + MPEG-TS payload | YUV4MPEG2 header + FRAME blocks |
| Types / schema | MPEG-2/H.264 + subtitles | Raw YUV frames |
| Compatibility | ffmpeg, Windows Media Center | ffmpeg, x264, vapoursynth |
| Best for | PVR archive migration | Filter-pipeline interchange |
How to convert WTV to Y4M
- 1
Select your files
Drag & drop your WTV files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to Y4M". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted Y4M file individually, or grab everything at once as a ZIP archive.
About the WTV format
WTV is Windows Media Center's recording format — what a tuner card wrote when you scheduled a TV show. Inside sits the broadcast transport stream (MPEG-2 or H.264) plus title metadata, subtitle tracks and multiple audio languages, all wrapped in Microsoft's own container.
Media Center died with Windows 10, but the recordings live on: ffmpeg reads WTV natively, so converting to MP4 or MKV keeps the content playable on any device with the metadata you actually care about.
+ Strengths
- ✓Complete tuner captures with subtitles
- ✓Multi-language audio preserved
- ✓ffmpeg decodes natively
! Limitations
- −DVR-MS (older) is a different format
- −Broadcast DRM variants exist
- −Copy-once flags block some captures
About the Y4M format
Y4M (YUV4MPEG2) is uncompressed video with a one-line text header: resolution, framerate and color space, then raw YUV frames. It is the lingua franca of video-filter pipelines — AviSynth, Vapoursynth and encoder test suites pass frames around as Y4M because there is nothing to misparse.
A Y4M of any real length is enormous (30MB per second of 1080p), so conversion to MP4/WEBM with H.264 or VP9 is always the destination — the value is in the zero-ambiguity input, not the format itself.
+ Strengths
- ✓Zero-ambiguity pixel format declaration
- ✓Standard between filter frameworks
- ✓Lossless by construction
! Limitations
- −No compression whatsoever
- −Color space variants (limited/full) trip decoders
- −Not natively playable in browsers
Why convert WTV to Y4M?
Converting makes sense where the strengths of Y4M meet what WTV cannot give you. Zero-ambiguity pixel format declaration Meanwhile DVR-MS (older) is a different format One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this WTV to Y4M converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for WTV to Y4M?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Why is video conversion slower than image conversion?
Every frame has to be decoded and re-encoded. This site runs that work on your own CPU via WebAssembly — nothing is uploaded, but a multi-minute video reasonably takes a few minutes. Images, by comparison, are single-frame jobs.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of Y4M, staying in sync with the video. If your WTV file has multiple audio tracks, the first one is used.