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How to Convert AV1 to WebM Online - Step by Step

AV1 to WebM Converter Online remuxes your AV1 video into a WebM container in three steps. No install required; the conversion runs in your browser via WebAssembly.


Step 1 - open the converter

Go to AV1 to WebM Converter Online. The page loads without any sign-in or plugin.


Step 2 - upload your file

Click the upload area or drag your .av1 (or .mkv/.mp4 with an AV1 track) onto the page. On the first conversion the tool downloads the FFmpeg.wasm engine - a one-time 31 MB download that is then cached by your browser. Progress messages appear while FFmpeg initialises and processes your file.


Step 3 - download the result

When the conversion finishes, a "Download" link appears. The file is saved as output.webm. The video quality is identical to the input - the tool uses stream copy (-c copy), so no re-encoding takes place. If you are not sure this fits your file yet, When to Use an AV1 to WebM Converter Online covers which downstream players and platforms actually call for the .webm container.

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Reviewed by the Free Tool Online editorial team · Tested in the current versions of Chrome, Firefox, Safari, and Edge before publishing. No account is needed to use any tool. Report a bug - we triage within 72 hours. · Last refreshed April 2026.

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