LOCAL VIDEO TOOLS · NEXT-GEN CODEC
AV1 to MP4 Converter
AV1 plays on new phones and recent graphics cards, and nowhere else. This page decodes it with your browser and writes an H.264 MP4 on your device.
Choose a file. It stays on your device.
How to convert an AV1 video to H.264 MP4
- 1
Add the AV1 file. MP4, MKV, WebM and raw IVF are all accepted.
- 2
Convert. Your browser decodes AV1; the page encodes H.264 and muxes the audio.
- 3
Download the MP4 and open it on the device that refused the AV1 file.
The problem is the decoder, not the file
AV1 is a codec, so it can live inside an MP4, an MKV or a WebM. That is why a file called clip.mp4 can still fail on a TV: the container is fine and the decoder is missing. Software AV1 decoding is expensive, so hardware support arrived only recently, on RTX 30 series and later, recent Intel and AMD chips, and Apple M3 and later.
Everything older, which is most TVs, most laptops and every editor from a few years ago, treats the file as unreadable. Re-encoding to H.264 is the practical fix, and H.264 playback is close to universal.
How this works without downloading a decoder
The page does not ship an AV1 decoder. It asks the browser for one through WebCodecs, the same interface a video call uses, and receives decoded frames that a second WebCodecs encoder turns into H.264. ffmpeg.wasm, which is already on this site, only repackages the bitstream and muxes the result.
That keeps the download small and the licence clean, and the conversion runs at hardware speed when your machine has AV1 decode. If the browser has no AV1 support at all, the page says so instead of failing silently. Chrome, Edge and Firefox on desktop handle it; Safari depends on the hardware.
What the MP4 keeps
- Picture: the first video track, at the original resolution, rewritten as 8-bit H.264.
- Sound: the first audio track, re-encoded to 128 kbps AAC.
- Dropped: subtitles, extra audio tracks, chapters and any HDR metadata.
10-bit AV1 is converted down to 8-bit, which is what H.264 at this profile expects. HDR is not tone-mapped, so a very bright HDR grade can look flatter after conversion. If colour accuracy matters more than compatibility, keep the AV1 master.
Why the result is usually bigger
AV1 stores the same picture in roughly half the bits that H.264 needs, sometimes less. A 40 MB AV1 file can easily become 90 MB of H.264 at comparable quality. That is the trade: a file that plays everywhere at the cost of space.
If the size matters, compress the MP4 afterwards, or accept a slightly softer picture. Converting an AV1 file to save space is the one thing this page cannot do.
FAQ
Is AV1 the same thing as MP4?
No. AV1 is a video codec, MP4 is a container. An MP4 can hold AV1, H.264 or HEVC, and the extension alone tells you nothing about which one is inside.
Why does this page not download a decoder?
It borrows the one in your browser. That keeps the page light and avoids shipping a licensed binary; the trade-off is that very old browsers cannot run the conversion.
Does it work with an AV1 file inside an MKV?
Yes. The container is unpacked first, then the AV1 stream is decoded. MKV, WebM, MP4 and IVF are all handled.
Where do AV1 videos come from?
YouTube and other streaming sites serve AV1 to save bandwidth, and newer cameras and encoders can write it. Files exported for archival are often 10-bit AV1.
Will HDR survive the conversion?
No. The output is standard dynamic range 8-bit H.264, so HDR highlights are clipped rather than mapped.
How long does a conversion take?
A few seconds for a short clip on a machine with AV1 hardware decode, longer in software. The time depends on your device, not on a queue.
Is the file uploaded?
No. Decoding, encoding and muxing all happen in this tab.