Regex for Alphanumeric Only

Validates strings containing only letters and numbers.

Pattern

/^[a-zA-Z0-9]+$/

Live Tester

Enter a string to test

Examples

✓ Hello123

✓ abc

✓ 456

✗ hello world

✗ test!

✗ a-b

Pattern Breakdown

^[a-zA-Z0-9]+ — alphanumeric from start

$ — to end

Code Snippets

Javascript

/^[a-zA-Z0-9]+$/.test("Hello123"); // true

Python

bool(re.match(r"^[a-zA-Z0-9]+$", "Hello123"))  # True

Php

preg_match('/^[a-zA-Z0-9]+$/', "Hello123"); // 1

Related Patterns

Email Address /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/ URL /^https?:\/\/(www\.)?[a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([a-zA-Z0-9()@:%_+.~#?&/=-]*)$/ Phone Number (International) /^\+?[1-9]\d{1,14}$/ Phone Number (US) /^$?[2-9]\d{2}$?[-.\s]?\d{3}[-.\s]?\d{4}$/ Phone Number (EU) /^\+?[1-9][0-9]{0,3}[\s.-]?$?[0-9]{1,5}$?[\s.-]?[0-9]{1,5}[\s.-]?[0-9]{1,5}$/ IPv4 Address /^((25[0-5]|2[0-4]\d|[01]?\d\d?)\.){3}(25[0-5]|2[0-4]\d|[01]?\d\d?)$/

Frequently Asked Questions

What is the regex for Alphanumeric Only?▾

The regex pattern for Alphanumeric Only is /^[a-zA-Z0-9]+$/. Validates strings containing only letters and numbers.

How do I use the Alphanumeric Only regex in JavaScript?▾

In JavaScript you create the pattern with a regex literal or the RegExp constructor and call .test() to check a string against it. A ready-to-copy example is shown in the Code Snippets section above, alongside Python and PHP versions.

What does the Alphanumeric Only pattern match?▾

It matches strings like Hello123; it rejects strings like hello world. See the Examples section above for the full list of matching and non-matching cases.