Can I convert old AVI files to MP4?

Yes. The embedded FFmpeg engine supports many AVI codecs and re-encodes readable files as modern H.264/AAC MP4 video.

Will AVI to MP4 improve video quality?

No converter can restore detail missing from the source. Keep Original resolution avoids artificial upscaling, while High Quality minimizes additional compression loss.

Why will my AVI not play in a browser?

AVI is a container that may contain older codecs browsers do not decode. Converting to H.264/AAC MP4 resolves most compatibility problems.

Do I need to install an AVI codec pack?

No. The browser downloads Zolkit's FFmpeg WebAssembly engine and decodes supported AVI codecs without a system codec pack.

AVI to MP4 Converter

Convert AVI to MP4 free in your browser. Update old AVI videos to compatible H.264 MP4 without an upload, account, or watermark.

Drop your AVI file here

or click to choose a file

MP4, MOV, AVI, MKV, WebM, WMV, MPG, VOB, TS, FLV, 3GP, HEVC and GIF

Conversion settings

Output format

QualityMaximum resolutionEncoding mode

AVI is an older container found in camera archives, Windows software, and legacy downloads. Its video codec may not play in browsers or modern mobile apps even when the .avi file itself opens on a PC. This preset decodes the AVI and creates a modern MP4 with H.264 video and AAC audio. That makes sharing, web playback, and editing easier. For low-resolution source footage, Keep Original avoids unnecessary upscaling. Processing is local and does not expose archival footage to a conversion service.

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Free Video Converter for MP4, MOV, MKV, WebM and More

Zolkit's Video Converter changes video formats entirely inside your browser. Convert MOV to MP4, MKV to MP4, WebM to MP4, AVI to MP4, MP4 to WebM, video to GIF, and other common combinations without uploading the source to a server. FFmpeg WebAssembly uses your device's processor for private local conversion, while quality, resolution, and encoding controls let you choose between speed and file size.

Local and private

Video bytes stay on your device; conversion runs inside the browser tab with no media upload.

Fast encoding mode

The default fast preset uses more of your browser's available CPU to finish common conversions sooner.

Nine output formats

Export MP4, MOV, AVI, MKV, WebM, WMV, MPG, FLV, or an animated GIF from one converter.

Quality controls

Choose high quality, balanced output, or a smaller file and optionally cap resolution at 1080p, 720p, or 480p.

Preview before saving

Play compatible results or preview an animated GIF before downloading the converted file.

Free without watermarks

Convert videos without an account, subscription, queue, watermark, or server-side file limit.

How to Convert a Video Format

1
Drop a video onto the converter or click the upload area to choose MP4, MOV, AVI, MKV, WebM, WMV, MPG, VOB, TS, FLV, 3GP, HEVC, or GIF.
2
Choose an output format, quality, maximum resolution, and encoding mode. Fast and balanced settings work well for most videos.
3
Select Convert, keep the tab open while your browser processes the file, then preview and download the result.