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Hexadecimal Number Regex Pattern

Validates hexadecimal numbers with optional 0x prefix. Used in color codes, memory addresses, and low-level programming.

#
Numbers
Beginner
Difficulty
Universal
Language
none
Flags
// Regular Expression
/^(0x)?[0-9a-fA-F]+$/

Live Regex Tester

Pattern Breakdown

^(0x)?[0-9a-fA-F]+$
Character class [ ]
Group ( )
Quantifier { }
Anchor ^ $
Repetition * + ?
Escape \
Alternation |
Any char .

Code Examples

JavaScript

const regex = /^(0x)?[0-9a-fA-F]+$/;
const test = "0xFF00FF";
console.log(regex.test(test)); // true

// Extract matches
const matches = test.match(regex);
console.log(matches);

Python

import re

pattern = r'^(0x)?[0-9a-fA-F]+$'
test = "0xFF00FF"
match = re.search(pattern, test)
print(match)  # Found!

Go

package main

import (
    "fmt"
    "regexp"
)

func main() {
    re := regexp.MustCompile(`^(0x)?[0-9a-fA-F]+$`)
    fmt.Println(re.MatchString("0xFF00FF")) // true
}

Common Use Cases

Color codesmemory addressesbinary data representation

Match Examples

InputResult
0xFF00FFMatch
0xGGNo Match

About the Hexadecimal Number Regex

Validates hexadecimal numbers with optional 0x prefix. Used in color codes, memory addresses, and low-level programming.

Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The hexadecimal number pattern is classified as beginner difficulty in the numbers category. It works in all major programming languages.

When using this regex, always consider edge cases and test thoroughly with real-world data. Use the interactive tester above to validate the pattern against your specific inputs before deploying to production.

Need More Regex Patterns?

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Frequently Asked Questions

What is the Hexadecimal Number regex pattern?

Validates hexadecimal numbers with optional 0x prefix. Used in color codes, memory addresses, and low-level programming.

How do I use the Hexadecimal Number regex?

Use the pattern /^(0x)?[0-9a-fA-F]+$/ in your code. In JavaScript: new RegExp('^(0x)?[0-9a-fA-F]+$', ''). Test it above with your own input.

What does this Hexadecimal Number regex match?

This pattern matches: "0xFF00FF". It does NOT match: "0xGG". Color codes, memory addresses, binary data representation.

Is the Hexadecimal Number regex beginner-friendly?

This pattern is rated Beginner. It uses basic regex syntax and is easy to understand.

What languages support the Hexadecimal Number regex?

This pattern works in all major programming languages including JavaScript, Python, Java, C#, Go, Ruby, PHP, and more. Syntax may vary slightly between regex engines.

Can I modify the Hexadecimal Number regex for my use case?

Yes! Use the interactive tester above to modify the pattern and test with your own data. Common modifications include making it case-insensitive (add 'i' flag), matching globally (add 'g' flag), or adjusting character classes.

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