What is an example of a matching and non-matching string?

A valid matching string is "cl01abcde000001l0abcdefgh". A non-matching string is "INVALID_CUID_WITH_UPPERCASE!".

Is this regex safe from ReDoS (Catastrophic Backtracking)?

Yes, this pattern is optimized for linear execution time and safe for browser-side validation without locking up the UI thread.

HomeRegex LibraryCUID & CUID2 Collision-Resistant ID Regex

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CUID & CUID2 Collision-Resistant ID Regex

Q: How do I test this regex in JavaScript and TypeScript?

Use regex.test(): const regex = /^[a-z0-9]{24,32}$/; const isValid = regex.test(inputString);

Validates modern secure collision-resistant identifiers (CUID and CUID2) used in high-scale distributed systems.

Regular Expression Pattern:

/^[a-z0-9]{24,32}$/

Valid Match Example:

cl01abcde000001l0abcdefgh

Invalid / Non-Match Example:

INVALID_CUID_WITH_UPPERCASE!

Regex Syntax Breakdown & Explanation

•^[a-z0-9]{24,32}$ : Matches lowercase alphanumeric string between 24 and 32 characters

Implementation in Popular Languages

JavaScript / TypeScript

const regex = /^[a-z0-9]{24,32}$/;
const isValid = regex.test("cl01abcde000001l0abcdefgh");
console.log(isValid); // true

Python (re)

import re

pattern = r"^[a-z0-9]{24,32}$"
match = re.match(pattern, "cl01abcde000001l0abcdefgh")
print(bool(match)) # True

Go (regexp)

package main
import (
  "fmt"
  "regexp"
)

func main() {
  re := regexp.MustCompile(`^[a-z0-9]{24,32}$`)
  fmt.Println(re.MatchString("cl01abcde000001l0abcdefgh"))
}

Frequently Asked Questions

Everything you need to know regarding specifications, syntax, and security best practices.

The regular expression pattern is /^[a-z0-9]{24,32}$/. Validates modern secure collision-resistant identifiers (CUID and CUID2) used in high-scale distributed systems.