HTML Tag regex

Matches paired HTML tags with content.

/<([a-z][a-z0-9]*)\b[^>]*>.*?</\1>/gi

What it matches

An opening tag, its attributes, the content, and a matching closing tag. The backreference \1 is the point: it captures the tag name and requires the same name to close, so <div>…</div> matches but <div>…</span> does not. The lazy .*? stops at the first valid close rather than the last.

Railroad diagram

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Breakdown

gFind all matches instead of stopping after the first

iLetters match both upper and lower case

<Literal "<"

[a-z]Match one of: Literal "a"–Literal "z"

[a-z0-9]*Match one of: Literal "a"–Literal "z", Literal "0"–Literal "9", zero or more

\bWord boundary

[^>]*Match not one of: Literal ">", zero or more

>Literal ">"

.*?Any character, zero or more (lazy)

<Literal "<"

\/Literal "/"

\1Backreference to group #1

>Literal ">"

Test cases

Matches

<div class="test">Hello</div>
<p>World</p>
<span id="x">y</span>

Does not match

<br />
<div>unclosed
plain text

Caveats

Fine for a quick scan, wrong for parsing. Nesting defeats it: the lazy quantifier closes <div><div>a</div></div> at the inner tag. It cannot see comments or CDATA, and content spanning a newline needs the s flag. HTML is not a regular language; for anything real, use a parser.

More web patterns

Test this against your own input in the regex tester, browse the full pattern library, or check the syntax cheat sheet.