AVI to MP4 Converter

Bring older AVI footage into a modern MP4 workflow. Useful for DivX/Xvid archives, MJPEG camera files, capture-card exports, and Windows-era video collections.

Drag & Drop Your Video

or click to browse — any video format

Output Format
Quality (CRF)
Trim (optional)

AVI is a legacy container, so AVI to MP4 has a different purpose from generic conversion. These files often come from old digital cameras, archived downloads, CCTV systems, capture cards, or Windows software that depended on DivX, Xvid, MJPEG, or codec packs. MP4 makes that footage easier to play, upload, preview, and share on modern devices.

The converter decodes the AVI video and audio streams and exports H.264 video with AAC audio in an MP4 container. That modern combination works on iPhone, Android, Windows, macOS, smart TVs, browsers, and most editors without installing old codec packs. It can also reduce file size when the AVI uses inefficient compression.

Use trimming when you only need a scene from a long legacy file. Keep quality higher if the AVI contains small text, security footage, or low-resolution material that already looks rough. Some very old AVI files may be damaged or use unusual codecs; if conversion fails, try another browser or confirm the file opens in a desktop player first.

Why Use Our AVI to MP4 Converter

Universal Device Compatibility

AVI files often won't play on iPhones, iPads, or in web browsers without special codecs. MP4 plays everywhere. Every smartphone, tablet, computer, smart TV, and streaming platform supports it natively.

Handles All AVI Codecs

Whether your AVI uses DivX, Xvid, MJPEG, MPEG-4, or even H.264 inside AVI, our tool decodes it correctly. No need to install codec packs or wonder what codec your file uses.

Significant File Size Reduction

AVI files are often unnecessarily large due to inefficient or old codecs. Re-encoding to H.264 typically reduces file size by 50–70% while maintaining visual quality.

Smart Quality Preservation

The tool selects encoding parameters based on your source quality. No guesswork needed. High-quality AVI footage stays high quality; low-quality sources get appropriate compression.

Optional Video Trimming

Enable the trim feature to extract just a portion of your AVI file. Convert old home videos into shareable clips. Pull out key moments without editing the original.

100% Private Browser Processing

WebAssembly runs FFmpeg entirely on your device. Old family videos, archival footage, and sensitive content stays completely private. Nothing uploads anywhere.

Features

  • Targets old AVI material from DivX/Xvid downloads, MJPEG cameras, capture cards, surveillance exports, and Windows-era software
  • Creates H.264/AAC MP4 output so the footage plays without codec packs or legacy media players
  • Can reduce oversized AVI files when the source uses inefficient compression or unoptimized camera settings
  • Preserves the original frame size unless you choose conversion settings that intentionally resize the output
  • Trimming helps pull one useful scene from a long legacy recording before modernizing it
  • Best for reviving old video collections and preparing them for phones, browsers, cloud uploads, or editing apps

How It Works

  1. 1

    Select your AVI file

    Click or drag and drop any AVI video. The tool handles files from old digital cameras, legacy software, surveillance systems, and downloaded content. Any codec inside AVI is supported.

  2. 2

    Optional: trim the video

    If you only need a portion of the AVI, enable the trim option and enter start and end timecodes. Extract just the segment you need for sharing or archiving.

  3. 3

    Convert in your browser

    Click Convert. WebAssembly decodes your AVI video and re-encodes it to H.264 MP4 locally on your device. A progress bar shows real-time processing status.

  4. 4

    Download your MP4

    Your MP4 downloads automatically. Play it on any device. IPhone, Android, Windows, Mac, smart TV. Or upload it directly to YouTube, social media, or cloud storage.

Who Should Use This Tool

People with old digital camera footage in AVI format wanting to play it on modern devices
Archivists and family historians converting legacy AVI videos to future-proof MP4 format
Users of older video editing software that outputs AVI needing web-compatible files
Anyone receiving AVI files that won't play on their phone, tablet, or smart TV
Content creators working with downloaded or archived AVI content from older sources
IT professionals converting surveillance or legacy system video for modern platforms

Frequently Asked Questions

What AVI codecs does this converter support?

Virtually all of them. The tool uses FFmpeg's comprehensive codec library, including DivX, Xvid, MJPEG (Motion JPEG), MPEG-4 Part 2, H.264 inside AVI, H.265/HEVC, Cinepak, Indeo, and many legacy codecs. If FFmpeg can decode it, our tool can convert it.

Will I lose quality converting AVI to MP4?

AVI to MP4 conversion involves re-encoding, which means some quality change from the compression. However, because MP4 uses modern H.264 encoding, the visual difference at the default quality setting is negligible for most content. For archival quality, use our higher bitrate options.

Why won't my AVI file play on my iPhone or iPad?

Apple devices only support a limited set of codecs. Primarily H.264 and HEVC. Older AVI files using DivX, Xvid, or MJPEG won't play on iOS devices. Converting to MP4 (H.264) makes them fully compatible with all Apple hardware.

How much will the file size decrease after conversion?

Typically 50–70% compared to the original AVI, depending on the source codec. Old DivX or MJPEG AVI files see the biggest reduction. Even H.264-in-AVI files benefit from the more efficient MP4 container structure.

Can I convert only a portion of the AVI file?

Yes. Enable the Trim option and specify start and end timecodes (HH:MM:SS). For example, 00:05:00 to 00:08:00 extracts a 3-minute segment from your AVI and converts it to MP4 without processing the entire file.

Does the converter handle AVI files with multiple audio tracks?

Yes. If your AVI contains multiple audio tracks, the tool processes the first (default) audio track. For files with multiple language dubs or commentary tracks, the primary audio stream is selected.

Is my AVI video uploaded to a server during conversion?

No. All processing happens locally in your browser using WebAssembly technology. Your AVI file is read from your device, decoded on your device, and the MP4 is saved to your device. Nothing is transmitted over the internet.

Can I batch convert multiple AVI files at once?

Currently, the tool processes one file at a time. For batch conversion, you can queue files sequentially. Each conversion runs locally, so you can start the next one as soon as the current one completes.

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