How much smaller will the WebM file be compared to AVI?

WebM files are typically 50-80% smaller than AVI files because VP9 compression is far more efficient than the older codecs typically found in AVI containers.

Can I use the WebM file on my website?

Yes. WebM is designed specifically for web use. All major browsers including Chrome, Firefox, Edge, and Safari support native WebM playback in HTML5 video elements.

Is the AVI to WebM conversion slow?

This conversion involves transcoding from AVI codecs to VP9, which requires more processing than a simple remux. Processing time depends on file length and your device's speed.

Will the conversion work with very old AVI files?

Yes. Our converter supports AVI files using virtually any codec, including legacy formats like DivX, Xvid, MPEG-1, and MPEG-2.

Does WebM support audio from my AVI file?

Yes. The audio from your AVI file is transcoded to Opus or Vorbis format, both of which are high-quality audio codecs supported within the WebM container.

AVI to WebM Converter

AVI files are far too large and poorly supported for web use. Converting AVI to WebM transforms your legacy videos into compact, browser-native files that load quickly and play seamlessly in HTML5 video elements. WebM's VP9 codec delivers strong visual quality at a fraction of the file size of a typical AVI.

100% Private — Your files never leave your device

Convert WebM to AVI instead

AVI to WebM involves full transcoding since the codecs differ entirely. VP9 is highly efficient and produces excellent visual results. For the best outcome, use AVI source files with the highest available quality since transcoding is a generational process.

How to Convert AVI to WebM

1
Upload your AVI video file using the drag-and-drop zone or file picker.
2
Select WebM as the output format.
3
Click Convert and download your web-optimized WebM video.

AVI vs WebM — Format Comparison

Feature	AVI	WebM
Full Name	Audio Video Interleave	WebM Video Format
Type	Video	Video
Codec	DivX / Xvid / H.264 / Uncompressed	VP8 / VP9 / AV1
Lossless	No	No
Extension	.avi	.webm
Best For	Legacy video archives	HTML5 web video

AVI Strengths

Wide compatibility with legacy systems
Simple file structure
Can contain uncompressed video for editing

WebM Strengths

Royalty-free and open source
Excellent compression for web streaming
Native support in all modern browsers

Frequently Asked Questions

When to Convert AVI to WebM

Publishing legacy AVI footage on modern websites and blogs
Dramatically reducing video file sizes for web delivery
Creating browser-compatible versions of archived AVI recordings
Building HTML5 video galleries from older AVI content

Related Conversions

AVIMP4 AVIMOV AVIMKV AVIMP3 MP4WebM MOVWebM MKVWebM

About Our AVI to WebM Converter

This converter uses FFmpeg compiled to WebAssembly (WASM) to transform your AVI files into WebM format entirely inside your web browser. When you select a file for conversion, the processing happens locally on your device. Your file is never uploaded to any server, never transmitted over the internet, and never stored anywhere outside your own computer. This privacy-first architecture makes our tool safe for confidential and sensitive content — including legal recordings, medical files, financial presentations, personal media, and any other material you would not want on a third-party server.

The conversion process works by decoding the AVI input using FFmpeg's highly optimized decoders, then encoding the output in WebM format with carefully tuned settings that balance quality and file size. When possible, the tool uses stream copy mode to remux (rewrap) compatible streams without re-encoding, which preserves the original quality with zero generational loss. When re-encoding is necessary due to codec differences between the two formats, the converter uses high-quality encoding settings to minimize any visible or audible quality reduction.

Supported input formats include MP4, MOV, AVI, MKV, and WebM for video, with automatic detection of the codecs and parameters inside your source file. The output is optimized for maximum compatibility with modern devices and platforms including Windows, macOS, Linux, iOS, Android, smart TVs, and all major web browsers.

Why browser-based conversion is safer: traditional online converters require you to upload your file to a remote server, where it is processed by third-party infrastructure and then made available for download. This workflow exposes your data to interception during upload, unauthorized access on the server, unclear data retention policies, and potential data breaches. Professionals in regulated industries such as healthcare (HIPAA), legal (attorney-client privilege), and finance (SOX, GDPR) often cannot use server-based converters without violating compliance requirements. Our WebAssembly-powered approach eliminates all of these risks by ensuring your data never leaves the browser sandbox on your own device.

The tool handles files up to 500 MB on desktop browsers and 200 MB on mobile devices. No account registration, no software installation, and no recurring subscription is required. Conversion typically completes in seconds for small files and a few minutes for larger ones, depending on your device's processing capabilities. Once the conversion is finished, you can download the result immediately and the source data is discarded from browser memory.