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Jay PadimalaMarch 20265 min read
Video Tools5 min read

Convert AVI to MP4 Free — Online AVI Converter

Convert AVI to MP4 online for free. Transform legacy AVI videos to modern MP4 format. No software install needed.

950 words

Access and pricing

Supported tools include 5 free on-device uses per day, shared across eligible tools. On compatible devices, guest access needs no sign-in. Signed-in users also get 5 daily eligible on-device uses. AI and cloud processing use credits separately.

New accounts can claim 20 welcome credits once. Eligible offers in MiOffice can earn up to 80 reward credits; offer conditions apply.

Starter costs $6.99/month and includes 250 credits at each paid renewal plus unlimited eligible local processing. Unused credits roll over. The $2.99 Day Pass covers 24 hours of eligible local processing; AI and cloud credits are separate.

Compare tools using a representative file and inspect the export. Check supported formats, device compatibility, processing location and the displayed cost before starting. This article is published by MiOffice; consider its recommendations with that affiliation in mind.

Pricing

Access and pricing updated October 30, 2026. This editorial update does not indicate a new test run.

AVI (Audio Video Interleave) is a legacy format from 1992 that you still encounter in old camcorder recordings, CCTV footage, legacy archives, and downloads from older sources. While AVI served well for decades, it produces large files and has poor compatibility with modern devices and platforms.

MiOffice converts AVI to MP4 directly in your browser. No installation, no upload, Guest access on supported tools; AI requires sign-in and credits. FFmpeg WebAssembly handles the conversion locally on your device.

How to Convert AVI to MP4

  1. 1

    Open the AVI to MP4 Converter

    Go to the AVI to MP4 converter.

  2. 2

    Select Your AVI Files

    Drag and drop your AVI file(s). Choose quality level (High, Medium, Low).

  3. 3

    Download MP4

    Click convert. Your modern, compact MP4 files are ready to use anywhere.

AVI vs MP4: Size and Compatibility

MetricAVIMP4 (H.264)
1 min 1080p (typical)200-500 MB30-60 MB
Phone playbackNot supportedNative
Social media uploadRejectedAccepted everywhere
Streaming supportNoYes
Year created19922001

Common AVI Sources

  • --Old camcorders: MiniDV and early digital camcorders exported AVI by default.
  • --CCTV footage: Many security systems still record in AVI format.
  • --Legacy downloads: Older media archives and file-sharing networks used AVI extensively.
  • --Screen capture software: Some older screen recorders default to AVI output.

Privacy

CCTV footage and personal camcorder recordings contain sensitive content. MiOffice processes everything locally in your browser -- no server upload, no data collection. Your files stay on your device.

Process Your Video Now

MiOffice AI is an AI-powered digital workspace studio. Create, edit, convert, compress, collaborate, and share — video, audio, images, documents, scanning, notes, screen sharing, and file transfer. the full MiOffice catalog, all in one place.

Get StartedLocal and cloud processing have different privacy terms

Frequently Asked Questions

Why are AVI files so large?
AVI was designed in 1992 when storage was cheap and bandwidth was not a concern. Many AVI files use minimal or no compression, resulting in files 5-10x larger than equivalent MP4. Converting to MP4 with H.264 dramatically reduces file size.
Can I convert old AVI files from my camcorder?
Yes. MiOffice supports AVI files with various codecs including DivX, Xvid, MJPEG, and uncompressed video. FFmpeg handles virtually all AVI variants.
Will I lose quality converting AVI to MP4?
If the AVI uses an uncompressed or lossless codec, converting to MP4 (H.264) introduces some compression. At High quality settings, the difference is negligible. If the AVI already uses a lossy codec, conversion at high quality produces equivalent output.
Can I batch convert AVI files?
Yes. Select up to 10 AVI files at once for batch conversion to MP4.

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Jay Padimala

CEO & Founder

Jay Padimala is CEO and Founder of MiOffice, a product of JSVV SOLS LLC.

View all posts by Jay Padimala
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