AVI vs MP4 — Differences, File Size & When to Use Each

AVI vs MP4

A detailed comparison of AVI Video and MP4 Video — file size, quality, compatibility, and which format to choose for your workflow.

Convert AVI → MP4 Convert MP4 → AVI

AVI

AVI Video

Video Files

AVI is a legacy Microsoft multimedia container that stores audio and video data. While largely superseded by modern formats, it remains widely recognized and is produced by many older devices and screen recorders.

About AVI files

MP4

MP4 Video

Video Files

MP4 is the most universally supported video container format. It typically uses H.264 or H.265 video codecs with AAC audio, providing an excellent balance of quality and file size across all devices and platforms.

About MP4 files

Strengths Comparison

AVI Strengths

Simple, well-documented format — trivial for any video library to parse.
Universal Windows playback since Video for Windows in 1992.
Low encoding overhead — interleaved structure is fast to write.
Works with any codec technically, including modern ones.

MP4 Strengths

Universal playback — every browser, phone, TV, game console, and editing suite reads MP4.
Supports modern codecs (H.264, H.265, AV1) with no container changes.
Progressive streaming works with the "moov atom" at the start of the file.
Carries subtitles, chapters, multiple audio tracks, and embedded metadata.
ISO-standardized (ISO/IEC 14496-14) and patent-licensable via MPEG LA.

Limitations

AVI Limitations

Aging container — no native support for chapters, subtitles, or multi-audio selection.
File-size limits (2 GB original, 4 GB with OpenDML) break for HD content.
Variable-framerate video causes sync drift.
Larger than equivalent MP4 or MKV due to container overhead.
Poor support on iOS and Android.

MP4 Limitations

Codec licensing (H.264, H.265) carries royalty costs for commercial use.
Streaming requires the moov atom at the start — a misplaced atom breaks web playback.
Not ideal for lossless or professional editing workflows (use ProRes or DNxHD instead).
Editing an MP4 almost always re-encodes, degrading quality.

Technical Specifications

Specification	AVI	MP4
MIME type	video/x-msvideo	video/mp4
Extension	.avi	—
Container	RIFF	ISO Base Media File Format (ISO/IEC 14496-12)
Max file size	2 GB (original); 4 GB (OpenDML extension)	Practically ~16 TB; 2^63 bytes theoretical
Codec support	Any codec via FourCC identifiers	—
Common video codecs	—	H.264 (AVC), H.265 (HEVC), AV1, VP9
Common audio codecs	—	AAC, MP3, FLAC, Opus
Streaming	—	Supported with faststart (moov atom at front)

Typical File Sizes

AVI

10-min video (XviD / MP3) 100-200 MB
45-min TV episode (DivX) 350-700 MB
2-hour movie (DVD rip) 700 MB - 1.4 GB

MP4

Smartphone video (1080p, 1 min) 60–120 MB
4K video (1 min, H.265) 200–400 MB
Streamed movie (90 min, H.264) 1–4 GB
Social clip (15s, H.264, 720p) 3–8 MB

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Frequently Asked Questions

AVI (Audio Video Interleave) is a multimedia container format introduced by Microsoft in 1992. It interleaves audio and video data streams and supports various codecs, though it lacks native support for modern features like subtitles and chapters.

MP4 (MPEG-4 Part 14) is the most universal video container format, standardized by ISO in 2001. It typically holds H.264 or H.265 video with AAC audio and supports subtitles, chapters, and metadata.

AVI files play in VLC (recommended, free), Windows Media Player, KMPlayer, and most video editing software. Some AVI files may require specific codec packs depending on the encoding used.

MP4 files play on virtually every device and media player including VLC, Windows Media Player, QuickTime, and all web browsers. Smartphones and smart TVs also support MP4 natively.

MP4 is the better choice for almost all modern uses since it offers better compression, wider compatibility, and support for subtitles and chapters. AVI is mainly encountered with legacy video files and older camera recordings.

MP4 has broader device compatibility and is the standard for streaming and social media. MKV supports more audio tracks, subtitles, and codecs, making it better for archiving movies with multiple languages.