Step 1: Provide your MKV 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 AV1 files.
MKV to AV1 Conversion FAQ
How do I convert MKV to AV1 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 AV1 container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. MKV is codec-agnostic: H.264, HEVC, VP9 and AV1 video sit happily beside AAC, FLAC, Opus, DTS or Dolby audio in the same file. AV1 is a codec, not a container — the bitstream normally travels inside MP4 or WebM, paired with Opus or AAC audio.
Will the AV1 play in a browser when the MKV would not?
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Yes, and that is usually the whole reason for the conversion. An MKV embedded in a web page either shows a broken player or forces a download, because browsers ship no decoder for it. AV1 plays inline through the native HTML5 video element with no plugin and no external application. 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.
Is AV1 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 MKV to AV1 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 AV1 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 MKV with that track first (VLC or ffmpeg can do this), then convert it. AV1 is the royalty-free video codec the Alliance for Open Media released in 2018 as the successor to VP9.
Are subtitle tracks preserved when converting MKV to AV1?
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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 MKV to AV1?
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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 MKV to AV1 drops these attachments when AV1 is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep MKV as a backup if you depend on attached fonts.
Which codec does the AV1 output use by default?
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It depends on the AV1 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. AV1 encoding is slow, and hardware decoders only appeared in phones and TVs from about 2020 onward — older devices fall back to power-hungry software decoding.
How does HDR (HDR10, Dolby Vision) survive MKV to AV1?
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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 MKV can look washed out in the AV1.
Why is my AV1 file smaller / larger than the MKV 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 MKV 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 MKV to AV1 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.
