BytePane

JWT Token Regex Pattern

Validates JWT (JSON Web Token) structure with three Base64URL-encoded segments separated by dots.

🔐
Security & Auth
Intermediate
Difficulty
Universal
Language
none
Flags
// Regular Expression
/^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$/

Live Regex Tester

Pattern Breakdown

^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$
Character class [ ]
Group ( )
Quantifier { }
Anchor ^ $
Repetition * + ?
Escape \
Alternation |
Any char .

Code Examples

JavaScript

const regex = /^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$/;
const test = "eyJhbG.eyJzdW.SflKxw";
console.log(regex.test(test)); // true

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

Python

import re

pattern = r'^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$'
test = "eyJhbG.eyJzdW.SflKxw"
match = re.search(pattern, test)
print(match)  # Found!

Go

package main

import (
    "fmt"
    "regexp"
)

func main() {
    re := regexp.MustCompile(`^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$`)
    fmt.Println(re.MatchString("eyJhbG.eyJzdW.SflKxw")) // true
}

Common Use Cases

Token validationAPI authenticationsecurity auditing

Match Examples

InputResult
eyJhbG.eyJzdW.SflKxwMatch
not.a.jwt.tokenNo Match

About the JWT Token Regex

Validates JWT (JSON Web Token) structure with three Base64URL-encoded segments separated by dots.

Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The jwt token pattern is classified as intermediate difficulty in the security & auth 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.

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Frequently Asked Questions

What is the JWT Token regex pattern?

Validates JWT (JSON Web Token) structure with three Base64URL-encoded segments separated by dots.

How do I use the JWT Token regex?

Use the pattern /^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$/ in your code. In JavaScript: new RegExp('^[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+\.[A-Za-z0-9_-]+$', ''). Test it above with your own input.

What does this JWT Token regex match?

This pattern matches: "eyJhbG.eyJzdW.SflKxw". It does NOT match: "not.a.jwt.token". Token validation, API authentication, security auditing.

Is the JWT Token regex beginner-friendly?

This pattern is rated Intermediate. It uses some advanced features like character classes and quantifiers.

What languages support the JWT Token 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 JWT Token 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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