What is the regex for html attribute?

The regex pattern for html attribute is `([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']`. This pattern validates html attribute key-value pair (attr="value").

How do I use this regex in JavaScript?

In JavaScript, create the regex with `const regex = /([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']/;` 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'([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']', value)`. The raw string prefix (`r`) prevents Python from interpreting backslashes as escape characters.

Is this regex case-sensitive?

This pattern explicitly handles both uppercase and lowercase via the character classes. No additional flags needed.

Regex for HTML Attribute

Regex Pattern

([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']

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

Quick Answer

The regex pattern for html attribute is `([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']`. HTML attribute key-value pair (attr="value"). This works in JavaScript, Python, Ruby, PHP, Java, and most regex engines that support PCRE syntax.

Test Examples

Input	Result
class="my-class"	✓ Matches
id="header"	✓ Matches
data-value="123"	✓ Matches
class	✗ No match
="value"	✗ No match
123="invalid"	✗ No match

Code Examples

javascript

const regex = /([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']/;
const isValid = regex.test(value);

python

import re
pattern = r'([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']'
if re.match(pattern, value):
    print("valid")

ruby

pattern = /([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']/
if value =~ pattern
  puts "valid"
end

php

if (preg_match('/([a-zA-Z][a-zA-Z0-9-]*)\s*=\s*["']([^"']*)["']/', $value)) {
    echo "valid";
}

java

String pattern = "([a-zA-Z][a-zA-Z0-9-]*)\\s*=\\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 Self-Closing Tag

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

HTML Entity

HTML character entity (named or numeric)

Semantic HTML5 Tag

HTML5 semantic element tags

XML Namespace

XML namespace declaration (xmlns or xmlns:prefix)