Resources / M3U file format

What is an M3U file?

An M3U file is a small text playlist. It usually contains names and media paths or URLs; it does not normally contain the video or audio itself.

Updated July 30, 2026 · 4 min read

How the M3U file format works

A basic playlist has one media location per line. Extended M3U playlists commonly begin with #EXTM3U and use a metadata line such as #EXTINF immediately before the location it describes. The exact fields vary, so a compatible player should treat unknown metadata as optional.

#EXTM3U
#EXTINF:-1,Example item
https://media.example.com/stream.m3u8

The example above is only a format illustration. An M3U URL can also carry an access token or user details. Do not post a real playlist address publicly or send it to a shared device unless you intend to share access.

How to open an M3U file or URL

1. Check the source. Use a file or address supplied by a service you are allowed to access.
2. Use an M3U-compatible player. In Lumio, choose M3U when adding a source, then select a local file or paste the complete URL.
3. Verify the returned text. A playlist often starts with #EXTM3U. A login page or error page is not a valid playlist response.
4. Keep the original extension. Changing .m3u to .m3u8 does not fix encoding, credentials or connectivity.

Common M3U file problems

• The file opens as text: this is normal; an M3U file is text. Open it with a compatible media player to use the entries.
• Characters look wrong: the file may use a different character encoding. M3U8 normally identifies a UTF-8 playlist.
• The player shows no items: the URL may be expired, private or returning an error response.
• The browser cannot play it: a website needs an HTTPS source with suitable CORS headers. A native application can access sources directly.