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AVI to MP4

Convert AVI video files to modern MP4 format in your browser. AVI uses older codecs, is not supported on iPhone/iPad, and creates large files. MP4 with H.264 is 50–80% smaller at the same quality and plays on every device. No signup.

Drop your video anywhere, click to browse

MP4, MOV, AVI, MKV, WebM, FLV, WMV, VOB

Ctrl+Vto paste a copied file

Frequently Asked Questions

Why is AVI format outdated?▼
AVI (Audio Video Interleave) was developed by Microsoft in 1992. It is a container with limited support for modern codecs, chapters, subtitles, and metadata. MP4 is the modern replacement with better compression and universal compatibility.
How much smaller will the MP4 file be?▼
Typically 50–80% smaller than the original AVI at equivalent quality. An AVI that is 2 GB becomes roughly 300–700 MB as MP4 with H.264 encoding.
Does AVI to MP4 conversion affect video quality?▼
Re-encoding always involves some quality processing, but at the default quality settings (CRF 23 H.264), the visual difference is imperceptible.
Is the conversion done in the browser?▼
Yes. FFmpeg WebAssembly runs locally. No video file is uploaded.
Will the audio be preserved?▼
Yes. The original audio track is preserved and re-encoded to AAC in the MP4 output.