Securitypopular
MD5 Hash Regex Pattern
Matches a 32-character lowercase hexadecimal MD5 hash digest.
Pattern
^[a-f0-9]{32}$Tested examples
5d41402abc4b2a76b9719d911017c592d41d8cd98f00b204e9800998ecf8427e5D41402ABC4B2A76B9719D911017C592abc123not-a-hashTest it live
Live Regex TesterJS
0 matches/
/g
5d41402abc4b2a76b9719d911017c592 d41d8cd98f00b204e9800998ecf8427e
Use it in your language
Use it in
// JavaScript / Node.js
const regex = /^[a-f0-9]{32}$/;
const value = "5d41402abc4b2a76b9719d911017c592";
const isMatch = regex.test(value);
console.log(isMatch); // true / false
// Extract all matches
const matches = value.match(/^[a-f0-9]{32}$/g) || [];Tags
Frequently asked questions
How do I use the MD5 Hash regex pattern in JavaScript?
Wrap the pattern in slashes: const re = /^[a-f0-9]{32}$/; — then call re.test(value) to check a single value, or value.match(re) to find matches. The "Use it in" snippets above give you the exact code for 9 languages.
Is this md5 hash regex production-ready?
Yes — every pattern in the library is tested against valid and invalid examples. Still, regex is one layer in a defense-in-depth strategy: pair it with server-side validation (e.g. Luhn for credit cards, mod-97 for IBAN, real DNS lookup for emails) for critical inputs.
Why does my pattern fail in another language?
Different regex engines (PCRE, Java, Python, Go's RE2) support slightly different syntax. The most common gotchas: lookbehinds (not in RE2), named groups syntax, and how backslashes need to be escaped inside string literals. The code snippets above already escape correctly for each language.
Can I edit this pattern and test it live?
Yes — use the live tester above. Type your test string and toggle flags (g, i, m, s, u, y) to see matches highlighted instantly, including capture groups.
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Browse the full library — 209 tested regex patterns across 16 categories.