What Is a .m3u File? .m3u Format, MIME & How to Open

Quick facts

Extension.m3u

File typeM3U Audio

MIME typeaudio/x-mpegurl

CategoryAudio

Charset—

Compressible—

What is .m3u

What is a .m3u file?

A .m3u file is a M3U Audio. It is an audio format used to store music, voice and sound effects, either lossy or lossless.

In the mime-db registry it maps to audio/x-mpegurl. When serving .m3u over HTTP, set the Content-Type header as shown in Developer info below.

Related entities: it maps to audio/x-mpegurl and is used by M3U among others — and is delivered over HTTP via the Content-Type header.

How to open .m3u files

Use VLC or Windows Media Player to open and edit .m3u files.
Any text editor (Notepad, VS Code) can inspect the raw content as text.

Developer info

When served over HTTP, responses should set the following header:

Content-Type: audio/x-mpegurl

Common software that reads/writes .m3u:

VLCWindows Media PlayerAudacityQuickTime

Relation chain

.m3uextension of

format

M3U Audioserved as

mime type

audio/x-mpegurlsent via header

http header

Related extensions

Related MIME types

Related programming languages

M3U

.m3u .m3u8

Common uses

Music and podcasts
Sound effects
Voice recordings

How to edit .m3u files

Open the file with VLC, make your changes and save.
Most editors preserve the original formatting and encoding — avoid changing the charset.

How to create .m3u files

Create a new file and save it with the .m3u extension, or export this format from VLC.

Frequently asked questions

What programs can open .m3u files?

Common options include VLC, Windows Media Player, Audacity. You can also open many of these files with built-in viewers or a browser.

How do I create a .m3u file?

Create a new file in any text editor or the app that owns the format and save it with the .m3u extension.

What is the relationship between .m3u and the audio/x-mpegurl MIME type?

audio/x-mpegurl is the media type identifier used for .m3u files during network transfer (for example in the HTTP Content-Type header).

Sources & standards

Updated 2026-08-18

Explore this reference