Step 1: Provide your AVI 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 WebM files.
AVI to WebM Conversion FAQ
How do I convert AVI to WebM 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 WebM container without re-encoding it, MKV to MP4 among them, which is quick and loses no quality. Most pairs re-encode the video. AVI files predate modern codecs: expect MPEG-4 Part 2 (DivX/Xvid), Motion JPEG or raw uncompressed frames rather than H.264. WebM is deliberately narrow: VP8 or VP9 video (AV1 more recently) with Vorbis or Opus audio, and nothing else.
My AVI footage shows comb lines on movement — will that carry into the WebM?
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Yes. AVI content is often interlaced, because the format comes from the broadcast and DVD era, and this converter has no deinterlace option, so the combing carries into the WebM. If it matters, deinterlace the AVI first in a desktop tool such as HandBrake or ffmpeg (the yadif filter). AVI is Microsoft’s Audio Video Interleave, introduced in 1992 on top of the RIFF chunk format — one of the oldest containers still in circulation.
My AVI recordings are split into numbered parts — does WebM have the same limit?
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No, and that is one of the better reasons to move. The AVI container has a practical single-file ceiling that long or high-bitrate recordings run straight into, which is exactly why old captures arrive as part1, part2, part3. WebM has no equivalent limit, so the pieces can be rejoined into one continuous file. AVI has no native support for modern codecs, variable frame rate, soft subtitles or files over 4 GB without hacks, and its per-chunk overhead bloats the file.
Can I add selectable subtitles once the file is WebM?
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Yes. AVI has no usable soft-subtitle track, so subtitles for AVI content had to be burned into the picture or shipped as a separate sidecar file. WebM carries subtitles as their own selectable stream, so after conversion you can attach an SRT track the viewer can switch on, switch off or restyle.
My AVI has several audio tracks — do they all survive into the WebM?
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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 AVI with that track first (VLC or ffmpeg can do this), then convert it. AVI is trivially simple, which is exactly why ancient camcorders, capture cards, DVD ripping tools and Windows-era software all still emit it. WebM is a poor fit anywhere outside a browser — video editors, phones’ native galleries and Smart TVs largely ignore it.
Will the WebM play in a browser when the AVI would not?
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Yes, and that is usually the whole reason for the conversion. An AVI embedded in a web page either shows a broken player or forces a download, because browsers ship no decoder for it. WebM plays inline through the native HTML5 video element with no plugin and no external application. WebM plays natively in every modern browser with no plugin, no licence fee and no patent exposure, which makes it the default for web-embedded video.
Is it worth converting old AVI recordings to WebM at all?
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For anything you intend to keep, yes. AVI belongs to an earlier generation of video tooling and the software that reads it is steadily disappearing from phones, browsers and operating systems. Moving the footage to WebM now, while a clean decoder still exists, is the difference between an archive you can open in ten years and one you cannot.
Will multi-track audio survive AVI to WebM 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 WebM 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 AVI with that track first (VLC or ffmpeg can do this), then convert it. WebM is a strict subset of Matroska that Google published in 2010 specifically to give HTML5 video a royalty-free container.
Are subtitle tracks preserved when converting AVI to WebM?
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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 AVI to WebM?
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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 AVI to WebM drops these attachments when WebM is not MKV — the elementary streams convert, but the attached payload stays in the source. Keep AVI as a backup if you depend on attached fonts.
Which codec does the WebM output use by default?
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It depends on the WebM 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.
