AVI to MP4 Converter Online — Convert Locally
Convert AVI to compatible H.264 MP4 locally with FFmpeg WebAssembly.
Loading local video processor…
About this tool
This browser tool decodes supported AVI video and audio codecs and creates an H.264 and AAC MP4 for more convenient playback and sharing.
How to use
- Choose a supported video smaller than 200 MB.
- Select the output option, then start local processing.
- Preview and download the new video before closing the page.
Features
- AVI input validation.
- H.264 MP4 output.
- Continues without native AVI preview.
Common use cases
- Convert an older camera or software export.
- Play AVI content on an MP4-oriented device.
- Create a modern sharing copy.
Common issues and tips
- AVI files can contain uncommon legacy codecs that the local engine cannot decode.
- Large high-resolution AVI sources may use substantial browser memory.
Privacy
The video is processed locally in your browser with FFmpeg WebAssembly and is not uploaded to Tools12345.
Frequently asked questions
Can conversion work without preview?
Yes, browser preview support is separate from FFmpeg decoding.
Does it overwrite the AVI?
No, it creates a new MP4 download.
Why can an AVI fail?
The container may use a codec not compiled into the WebAssembly engine.