What is the regex for semantic html5 tag?

The regex pattern for semantic html5 tag is ` ]*)?>`. This pattern validates html5 semantic element tags.

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = / ]*)?>/;` and test with `regex.test(yourValue)`. It returns `true` if the value matches.

How do I use this regex in Python?

In Python, use `import re; re.match(r' ]*)?>', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

By default, yes. To make it case-insensitive, add the `i` flag in JavaScript (`/ ]*)?>/i`) or use `re.IGNORECASE` in Python.

Regex for Semantic HTML5 Tag

Regex Pattern

HTML5 semantic element tags

Quick Answer

Test Examples

Input	Result
<header>	✓ Matches
<main class="content">	✓ Matches
</footer>	✓ Matches
<nav>	✓ Matches
<div>	✗ No match
<span>	✗ No match
<p>	✗ No match
<custom-element>	✗ No match

Code Examples

javascript

const regex = /<\\/?(article|aside|details|figcaption|figure|footer|header|main|mark|nav|section|summary|time)(?:\s[^>]*)?>/;
const isValid = regex.test(value);

python

import re
pattern = r'<\/?(article|aside|details|figcaption|figure|footer|header|main|mark|nav|section|summary|time)(?:\s[^>]*)?>'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /<\/?(article|aside|details|figcaption|figure|footer|header|main|mark|nav|section|summary|time)(?:\s[^>]*)?>/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/<\\/?(article|aside|details|figcaption|figure|footer|header|main|mark|nav|section|summary|time)(?:\s[^>]*)?>/', $value)) {
    echo "valid";
}

java

String pattern = "<\\/?(article|aside|details|figcaption|figure|footer|header|main|mark|nav|section|summary|time)(?:\\s[^>]*)?>";
boolean isValid = value.matches(pattern);

Frequently Asked Questions

Related Regex Patterns

HTML Tag

Any HTML tag (opening, closing, or self-closing)

HTML Comment

HTML comment block (multi-line safe)

HTML Attribute

HTML attribute key-value pair (attr="value")

HTML Self-Closing Tag

Self-closing HTML tags like <br/>, <img/>, <input/>

HTML Entity

HTML character entity (named or numeric)

XML Namespace

XML namespace declaration (xmlns or xmlns:prefix)