Step 1: Transfer your WebM files using the button above or by slide and deposit.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Retrieve your converted AV1 files.
WebM to AV1 Conversion FAQ
How do I re-encode WebM to AV1 without losing video quality?
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Upload your WebM file and set Quality to High Quality in the conversion options. That re-encodes the video at the highest quality setting (CRF 18 for H.264 and VP9 output), which keeps the most detail at the cost of a larger file. The default, Balanced, uses the standard setting. The AV1 output gets a codec its container supports: H.264 for MP4, MOV and MKV, VP9 for WebM. WebM is deliberately narrow: VP8 or VP9 video (AV1 more recently) with Vorbis or Opus audio, and nothing else. AV1 is a codec, not a container — the bitstream normally travels inside MP4 or WebM, paired with Opus or AAC audio.
Can the AV1 hold more than one audio track?
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Yes, and it is a real upgrade over WebM. AV1 treats every audio stream as a first-class track, so an original-language mix, a dub and a director commentary can live in one file with the player switching between them on demand. 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.
Does AV1 support chapter markers that WebM did not?
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It does. AV1 stores chapters as container metadata, so a long recording can be navigated by section instead of by scrubbing a progress bar. WebM has nowhere to put that information, so the converted AV1 starts with no chapters; add markers afterwards with a tool such as MKVToolNix or ffmpeg.
Will the AV1 still play smoothly on a phone or a TV?
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It may not. WebM is decoded by dedicated silicon on phones, tablets and TVs, which is why it plays without flattening the battery. AV1 typically falls back to software decoding on the same hardware — higher CPU load, a warmer device, and dropped frames on 4K material. For a device target, WebM is the safer container to stay in. 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.
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.
Which video codec does the AV1 output use?
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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 is the royalty-free video codec the Alliance for Open Media released in 2018 as the successor to VP9.
Will my audio track survive WebM to AV1 conversion?
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Yes, the main audio track comes through, re-encoded to a codec the AV1 container plays, for example AAC in MP4 and MOV or Opus in WebM. Most conversions keep only that one track (the one with the most channels), so alternate languages and commentary are dropped. MP4 to MOV, and AVI, WMV, MPEG, FLV, VOB or M4V to MKV, keep every audio track.
Can I keep the original framerate when converting WebM to AV1?
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Yes. The frame rate is kept unless you change it: a 24 fps WebM stays 24 fps in the AV1. The Frame Rate setting can also convert to 60, 30 or 24 fps. It changes the rate only; it does not deinterlace the video or remove 3:2 pulldown.
How much will the file size change going from WebM to AV1?
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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 WebM 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.
Will the AV1 file play on iPhone, Android, and Smart TVs?
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MP4 with H.264 plays on practically every phone, browser and TV. MOV with H.264 plays on Apple devices and most TVs but not on every older Android phone. MKV needs an app such as VLC on iOS, and WebM is at home in browsers. There is no device preset on this page, so choose the target format your device supports.
How long does converting a 1-hour WebM video to AV1 take?
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There is no fixed time: it depends on the length, the resolution and the target format. Conversions run on our servers' CPUs with software encoders; there is no GPU acceleration. MKV to MP4 or MOV with the default settings copies the video stream and is the quickest. A re-encode to H.264 takes longer, and WebM (VP9) is the slowest target, several times slower than H.264 in our tests.
What is the maximum resolution supported for WebM to AV1?
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The converter has no resolution cap of its own; the limit is the upload size allowed on your plan, and the resolution stays as it is unless you choose 1080p, 720p or 480p. 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 untouched. A re-encode drops the HDR10 mastering metadata, and with a Quality, Resolution or Frame Rate setting some pairs also reduce the video to 8-bit colour, so an HDR WebM can look washed out.
AV1 is an open, royalty-free video compression format designed for efficient video streaming over the internet. It provides high compression efficiency without compromising visual quality.
