M3U validator

Checks expected M3U header, syntax, entries, missing URLs, and malformed records.

Paste M3U content

Validation runs locally in your browser. Nothing is uploaded.

Header

Present

Entries

Errors

What this check examines

Header: the file must open with #EXTM3U — missing headers fail strict TV parsers first.
Pairing: every #EXTINF needs its stream URL on the next non-comment line; orphans in either direction are flagged with line numbers.
Names and groups: empty display names and malformed attributes are reported, since they confuse players without breaking the parse.
URL shape: stream lines that do not look like stream locations are flagged for inspection.

Reading the report

Three numbers plus an error list (first 20 shown). Header missing means fix the top of the file; pairing errors name exact lines to repair top-down; a clean report with zero entries means a valid but empty file. The annotated walkthrough for each message lives in What is an M3U playlist?.

What this check cannot tell you

Whether URLs are reachable — syntax validation never fetches. Pair with the IPTV test for that.
Whether streams play — a perfectly valid file can reference all-dead URLs.
Encoding subtleties beyond structure: a file can pass here and still carry a BOM or mojibake that strict players reject. When validation passes but import fails, check encoding next.

FAQ

VLC plays my file but the validator flags errors. Who is right? Both, for different strictness levels. VLC tolerates what TV parsers reject — fix everything flagged, since the strictest player you own sets the bar.

Is my pasted content uploaded anywhere? No. Validation runs entirely in your browser; nothing leaves the page. That locality is deliberate, not incidental.

How strict should a “valid” file be? Strict enough for the worst parser you use. A file with zero errors imports everywhere; a file with “only warnings” imports somewhere.

Does it handle very large files? Yes, within reason — multi-megabyte pastes parse instantly in modern browsers. Past tens of megabytes, validate an excerpt around the failure instead of the whole file.

Method and limits

Methodology: the same parser this site documents runs locally on your input — no network, no uploads, no rate limits to hit. Error lists show the first 20 findings; fix those and re-run for the next layer.

Sources

RFC 8216 §4.1: header, encoding, and line rules behind these checks. Verified October 2026.
M3U format reference with the annotated report walkthrough.
Inspect and clean workflow placing validation between viewing and editing.