Securitypopular

SHA-256 Hash Regex Pattern

Matches a 64-character lowercase hexadecimal SHA-256 hash digest.

Pattern
^[a-f0-9]{64}$

Tested examples

e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
abc
AAF4C61DDCC5E8A2DABEDE0F3B482CD9AEA9434D

Test it live

Live Regex TesterJS
0 matches
/
/g
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824

Use it in your language

Use it in
// JavaScript / Node.js
const regex = /^[a-f0-9]{64}$/;
const value = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855";
const isMatch = regex.test(value);
console.log(isMatch); // true / false

// Extract all matches
const matches = value.match(/^[a-f0-9]{64}$/g) || [];

Tags

Frequently asked questions

How do I use the SHA-256 Hash regex pattern in JavaScript?
Wrap the pattern in slashes: const re = /^[a-f0-9]{64}$/; — 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 sha-256 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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