Step 1: Provide your AV1 files using the button above or by toss and let go.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Fetch your converted MP4 files.
AV1 to MP4 Conversion FAQ
How do I convert AV1 to MP4 without re-encoding the video stream?
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There is no stream-copy switch on this page. A few pairs copy a compatible video stream into the MP4 container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. AV1 is a codec, not a container — the bitstream normally travels inside MP4 or WebM, paired with Opus or AAC audio. Almost every MP4 in the wild is H.264 video with AAC audio; the container also legally holds HEVC, AV1 and VP9.
My AV1 has several audio tracks — do they all survive into the MP4?
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No. The converter keeps one audio track, the one with the most channels (normally the main mix), and drops the rest; there is no setting to pick a different one. To keep another track, remux the AV1 with that track first (VLC or ffmpeg can do this), then convert it. AV1 delivers roughly 30% better compression than H.264 at the same quality and carries no licence fees, which is why YouTube and Netflix push it. MP4 only supports one widely-honoured subtitle format (mov_text), and multi-track audio is unreliable outside desktop players.
Is MP4 a container or a codec, and does that change what I get back?
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It changes what to expect from the output file. One side of this conversion names an encoding rather than a wrapper, so what comes back is that bitstream inside whichever container suits it best — normally MP4 or MKV. The extension reflects the container; the codec is what actually determined the file size and where it will play.
Will multi-track audio survive AV1 to MP4 conversion?
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Usually not. Most conversions keep one audio track, the one with the most channels (normally the main mix), re-encoded for the MP4 container, so commentary and alternate-language tracks are dropped. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every track, and so does MP4 to MOV. To keep a different track, remux the AV1 with that track first (VLC or ffmpeg can do this), then convert it. MP4 is ISO/IEC 14496-14, standardised in 2001 and derived from the same QuickTime box layout MOV uses.
Are subtitle tracks preserved when converting AV1 to MP4?
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On some pairs. MP4 to MOV keeps every text subtitle track. AVI, WMV, MPEG, FLV, VOB and M4V to MKV keep every subtitle track: text subtitles are copied or converted to SRT, and picture-based subtitles such as DVD or Blu-ray ones are copied as they are. MP4, MOV and WebM to MKV keep only the first subtitle track (as ASS), and MP4 to WebM keeps the first one as WebVTT. Other pairs, including MKV to MP4 or MOV and WebM to MP4, drop subtitle tracks, and the converter does not burn them into the picture. Subtitles that are already burned in stay, because they are part of the video frames.
What about MKV attachments (fonts, cover art) when going AV1 to MP4?
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MKV is the only mainstream container that stores arbitrary attached files (TTF fonts for ASS subs, JPG cover art, fan-translated PDF inserts). Going from AV1 to MP4 drops these attachments when MP4 is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep AV1 as a backup if you depend on attached fonts.
Which codec does the MP4 output use by default?
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It depends on the MP4 container. MP4, MOV and MKV output use H.264, which plays on practically every phone, browser and TV. WebM output uses VP9. AVI, WMV and MPEG output use the older codecs those formats were designed for. MP4 is the safest possible delivery target — every phone, browser, console, editor and Smart TV built in the last decade plays it without extra software.
How does HDR (HDR10, Dolby Vision) survive AV1 to MP4?
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There is no HDR processing or tone mapping. When the video stream is copied (MKV to MP4 or MOV with the default settings), HDR10 passes through as it is. When the video is re-encoded, the HDR10 mastering metadata is dropped and Dolby Vision or HDR10+ data is not kept, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR AV1 can look washed out in the MP4.
Why is my MP4 file smaller / larger than the AV1 after conversion?
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It depends on what happens to the video. MKV to MP4 or MOV with the default settings copies the video stream unchanged, so the size stays close to the source. Most other pairs re-encode it: a high-bitrate AV1 usually comes out smaller, while an already heavily compressed one can grow. Smaller File under Quality gives the smallest output, and H.265 in the Codec setting (MP4, MOV and MKV) is usually smaller than H.264 at similar quality but plays on fewer devices.
Does the AV1 to MP4 converter handle 4K / 8K / 60fps content?
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The converter has no resolution cap of its own; the limit is the upload size allowed on your plan, and 4K, 8K and 60 fps files keep their resolution and frame rate unless you change them. MKV to MP4 or MOV with the default settings copies the video stream, which is quick at any resolution. Other pairs re-encode on CPU and the time grows with the pixel count, so a long 4K or 8K file takes much longer than the same length in 1080p.
