Y4M to APNG Converter
Processing entirely on your device — large files may take a moment.
YUV4MPEG2 Raw Video and Animated PNG 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 an animated GIF to APNG to keep smooth color and clean transparency while staying animated.
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 APNG
| Y4M | APNG | |
|---|---|---|
| Structure | YUV4MPEG2 header + FRAME blocks | PNG frames + acTL/fcTL chunks |
| Types / schema | Raw YUV frames | True color + full alpha |
| Compatibility | ffmpeg, x264, vapoursynth | Chrome, Firefox, Safari (all modern) |
| Best for | Filter-pipeline interchange | High-quality animation on the web |
How to convert Y4M to APNG
- 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 APNG". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted APNG 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 APNG format
APNG (Animated PNG) is what GIF should have been: the same PNG file format with an animation extension — every frame in full 24-bit color with 8-bit alpha, no 256-color palette, no binary transparency with jagged edges. All modern browsers render it natively.
GIF has one job APNG does better in every dimension: color fidelity and clean transparency for animation. Converting an animated GIF to APNG keeps every frame but upgrades color depth and kills the halo around transparent edges. The only cost is file size — true color costs bytes.
+Strengths
- ✓Full 24-bit color per frame (no 256-color palette)
- ✓8-bit alpha transparency — no jagged edges
- ✓Native rendering in every modern browser
!Limitations
- −Larger files than GIF for the same animation
- −Legacy tools may show only the first frame
- −Not accepted by some social platforms
Why convert Y4M to APNG?
Think of it as moving your file to the container that fits the job. No compression whatsoever APNG works differently: Full 24-bit color per frame (no 256-color palette) 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 APNG 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.
Will I lose quality converting Y4M to APNG?
No — APNG is a lossless format, so every pixel of the converted image matches your original Y4M file. You can also adjust the quality/size balance before converting when the target format supports compression.
Does converting Y4M to APNG re-encode my video?
Yes. The video is decoded and re-encoded with the settings chosen by the quality slider, which is what allows the format and size to change. For an archival copy, keep higher quality; for sharing, lower quality gives a much smaller file.
Will the audio track be kept?
Yes. The audio is carried over and re-encoded to the standard audio codec of APNG, staying in sync with the video. If your Y4M file has multiple audio tracks, the first one is used.