Video Formats Guide: MP4, MOV, AVI, MKV & WebM Explained

You've got video files in all sorts of formats — MP4, MOV, AVI, MKV, WebM. What's the difference? And does it matter when you want to extract audio? Let's break it down.

Understanding Video "Formats"

Here's something that confuses most people: when we say "video format," we're usually talking about the container, not the actual video encoding inside.

Think of it like a shipping box. The box (container) can hold different items (codecs). An MP4 file might contain H.264 video and AAC audio. An MKV file might contain the exact same video and audio, just in a different box.

For audio extraction, the container doesn't matter much — we care about what's inside.

The Common Video Formats

MP4 — The Universal Standard

Full name: MPEG-4 Part 14

Common codecs inside: H.264/H.265 video, AAC audio

Best for: Everything. Streaming, sharing, storing.

MP4 is the most widely supported video format. It plays on phones, computers, TVs, game consoles — everything. If you're not sure what format to use, MP4 is always a safe choice.

Audio extraction: Excellent. Usually contains high-quality AAC audio.

MOV — Apple's Format

Created by: Apple (QuickTime)

Common codecs inside: H.264, ProRes, AAC

Best for: Apple devices, professional video editing

MOV was developed by Apple for QuickTime. It's essentially similar to MP4 (they share the same underlying technology) but with some Apple-specific features. iPhones record video in MOV by default.

Audio extraction: Excellent. Similar to MP4.

AVI — The Windows Classic

Full name: Audio Video Interleave

Created by: Microsoft (1992)

Best for: Legacy content, Windows compatibility

AVI is ancient by digital standards. It works, but it's bulky and lacks modern features like streaming support. You'll encounter AVI files from old downloads or legacy systems.

Audio extraction: Good, though audio quality depends on the source.

MKV — The Feature-Rich Container

Full name: Matroska Video

Common codecs inside: Anything (H.264, H.265, VP9, etc.)

Best for: HD movies, TV shows, anime, multi-track content

MKV is the Swiss Army knife of video containers. It can hold virtually any codec, multiple audio tracks (different languages), subtitles, and chapter markers. It's popular for HD movie rips and anime releases.

Audio extraction: Excellent, often with multiple audio track options.

WebM — The Web Standard

Created by: Google

Common codecs inside: VP8/VP9 video, Vorbis/Opus audio

Best for: Web videos, HTML5, open-source projects

WebM was designed for the web — royalty-free, efficient, and well-supported by browsers. Many online video tools and websites use WebM internally.

Audio extraction: Good, typically contains Vorbis or Opus audio.

WMV — Windows Media Video

Created by: Microsoft

Best for: Windows-specific workflows, older content

WMV was Microsoft's answer to QuickTime. It's less common now but you'll still find WMV files from the 2000s or certain Windows applications.

Audio extraction: Moderate — depends on the encoding quality.

FLV — Flash Video

Created by: Adobe (Macromedia)

Best for: Legacy web content, old YouTube downloads

FLV was the dominant web video format before HTML5. Flash is dead now, but FLV files still exist from old downloads. If you have FLV files, you'll probably want to convert them to something modern.

Audio extraction: Works fine, though the format is obsolete.

Which Format Has the Best Audio?

The container doesn't determine audio quality — the codec inside does. That said, here's what you'll typically find:

• MP4/MOV: Usually AAC audio at 128-256kbps (good quality)
• MKV: Often AC3, DTS, or high-bitrate AAC (excellent quality)
• WebM: Vorbis or Opus (good quality, efficient)
• AVI: Varies wildly depending on the source

For audio extraction purposes, you'll get the best results from HD content (MKV files from movies, high-quality MP4 downloads). Low-resolution web videos tend to have more compressed audio.

Quick Reference Table

Format	Best For	Audio Quality
MP4	Everything	Good
MOV	Apple devices	Good
MKV	HD movies	Excellent
WebM	Web videos	Good
AVI	Legacy content	Varies

The Bottom Line

For audio extraction, the video format doesn't matter much — our converter handles all of them. What matters is the quality of the source. HD content will give you better audio than a low-res web video, regardless of the container format.