Y4M to MPEG Converter
Processing entirely on your device — large files may take a moment.
YUV4MPEG2 Raw Video and MPEG Program Stream exist for different jobs: Y4M is uncompressed video with a text header — the interchange format of video-filter pipelines (avisynth/vapoursynth) and encoder test suites. Convert .mpeg files exactly like .mpg — to MP4, MKV or modern codecs.
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 Y4M compares to MPEG
| Y4M | MPEG | |
|---|---|---|
| Compatibility | ffmpeg, x264, vapoursynth | Universal decode |
| Best for | Filter-pipeline interchange | Legacy disc and capture video |
How to convert Y4M to MPEG
- 1
Select your files
Drag & drop your Y4M 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 MPEG". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MPEG file individually, or grab everything at once as a ZIP archive.
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
About the MPEG format
MPG (MPEG program stream) usually means MPEG-1 or MPEG-2 video — the codecs of VCD, SVCD and DVD, and of countless home video captures in the 1990s and 2000s. MPEG-1 tops out around VHS-grade 352×288; MPEG-2 delivers proper standard definition and still runs inside broadcast and DVD infrastructure.
Playback compatibility is its superpower: MPEG-1/2 decode paths exist in every player and hardware made this century. Quality-to-bitrate efficiency, however, is a generation behind H.264 — converting old MPG files to MP4 typically halves their size.
+Strengths
- ✓Decodes on essentially every player and device
- ✓Simple, battle-tested standard
!Limitations
- −Inefficient codecs by modern standards
- −MPEG-1 is VHS-grade at best
Why convert Y4M to MPEG?
Think of it as moving your file to the container that fits the job. No compression whatsoever MPEG works differently: Decodes on essentially every player and device If any of that sounds like your task, run the conversion — it takes seconds and nothing leaves your device.
Frequently asked questions
Is this Y4M to MPEG 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 Y4M to MPEG?
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.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of MPEG, staying in sync with the video. If your Y4M file has multiple audio tracks, the first one is used.
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.