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WEBM
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AVI

WebM to AVI Converter — Free, Online, No Upload

Your old video editor doesn't understand WebM — AVI is the classic format that legacy software always opens.

Free · no signup2 free files a day100% in-browser · no upload

Tap to select WEBM files

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✓ Files never uploaded✓ 100% browser-based✓ No account required
Need the reverse?AVI → WEBM

How to convert WEBM to AVI online

  1. 1

    Drop your WEBM file

    Drag your WebM Video Format file onto the box above, or click it to pick a file.

  2. 2

    Wait a few seconds

    Conversion starts on its own and runs on your device, not on a server.

  3. 3

    Download your AVI

    Click Download to save the Audio Video Interleave file.

WEBM vs AVI: format overview

WEBM

WebM Video Format

Google (On2 Technologies) · 2010

Compression
lossy
Transparency
No
  • ✓ Royalty-free codec (VP8/VP9/AV1)
  • ✓ Excellent web streaming support
  • ✗ Not supported on iOS/Safari natively
AVI

Audio Video Interleave

Microsoft · 1992

Compression
lossy
Transparency
No
  • ✓ Universal Windows compatibility
  • ✓ Simple container format — widely supported

WEBM magic bytes: 1A 45 DF A3

AVI magic bytes: 52 49 46 46 xx xx xx xx 41 56 49 20

Why convert WEBM to AVI?

You downloaded a WebM video from a website, screen recorder, or web app export — and now your video editing software won't open it. WebM is a modern web format, but older video editors including VirtualDub, older versions of Sony Vegas, Windows Movie Maker, and various video processing tools were built before WebM existed and have no decoder for it. AVI is the legacy format these tools have always supported.

AVI is one of the oldest and most universally recognized video containers on Windows. Software from the early 2000s to today reads AVI without any additional codec installation, because AVI support is baked into Windows at the operating system level. Converting your WebM to AVI makes it immediately openable in virtually any Windows video application regardless of age.

The conversion requires full transcoding — WebM's VP8 or VP9 video is decoded and re-encoded to Xvid-style MPEG-4 inside the AVI container, and the Opus audio is re-encoded to 192 kbps MP3. The converter uses a fixed high quality level to keep visible artifacts small. AVI files will usually be larger than the WebM, because MPEG-4 Part 2 is an older, less efficient codec. This conversion is specifically for legacy software compatibility — for modern workflows, MKV or MP4 are better targets.

Quality & file size: WEBM to AVI

Typical sizes (1 minute 1080p): WEBM 50–200 MB → AVI 200–600 MB.

Frequently asked questions

Why would I convert a modern WebM to an old AVI format?
Legacy video editing software (older Premiere versions, Windows Movie Maker, VirtualDub) doesn't support WebM. Converting to AVI makes the video editable in these older tools without upgrading software.
Does WebM to AVI conversion reduce quality?
Some. The VP8/VP9 video is re-encoded to Xvid-style MPEG-4 at a fixed high quality, and the Opus sound to 192 kbps MP3. For most clips the difference is hard to see, but the AVI is usually larger.

Your WEBM file never leaves this tab — FormatDrop has no endpoint that receives file data. How it works