Y4M to MOV Converter
Processing entirely on your device — large files may take a moment.
MOV keeps high production quality, which makes it a favourite intermediate format for video editing before final export. If your files are still in Y4M format, this page is the shortcut: Y4M is uncompressed video with a text header — the interchange format of video-filter pipelines (avisynth/vapoursynth) and encoder test suites.
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 MOV
| Y4M | MOV | |
|---|---|---|
| Compatibility | ffmpeg, x264, vapoursynth | Best in Apple ecosystems |
| Best for | Filter-pipeline interchange | Editing intermediates, ProRes |
How to convert Y4M to MOV
- 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 MOV". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MOV 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 MOV format
MOV is Apple's QuickTime container, and technically the elder sibling of MP4 — same ISO base media format, same codec freedom. What sets it apart is professional video: ProRes intermediate codecs, timecode tracks and alpha channels live in MOV, which is why Final Cut, Premiere and every camera that shoots Apple ProRes hand you MOV files.
For everyday sharing it behaves exactly like MP4 (an H.264 MOV is interchangeable in practice). Where it hurts is size: ProRes and other editing codecs run hundreds of gigabytes per hour by design — they prioritize frame-accurate editing over compactness.
+ Strengths
- ✓Native to macOS, iOS and pro editing suites
- ✓Carries ProRes, alpha and timecode tracks
- ✓MP4-compatible for standard codecs
! Limitations
- −Editing codecs produce enormous files
- −ProRes playback needs capable hardware/players
Why convert Y4M to MOV?
Converting makes sense where the strengths of MOV meet what Y4M cannot give you. Native to macOS, iOS and pro editing suites Meanwhile No compression whatsoever One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this Y4M to MOV 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 MOV?
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 MOV, staying in sync with the video. If your Y4M file has multiple audio tracks, the first one is used.