BytePane

Base64 Encoded String Regex Pattern

Validates Base64-encoded strings with proper character set and optional padding. Used in data transfer and encoding.

🔐
Security & Auth
Beginner
Difficulty
Universal
Language
none
Flags
// Regular Expression
/^[A-Za-z0-9+/]+={0,2}$/

Live Regex Tester

Pattern Breakdown

^[A-Za-z0-9+/]+={0,2}$
Character class [ ]
Group ( )
Quantifier { }
Anchor ^ $
Repetition * + ?
Escape \
Alternation |
Any char .

Code Examples

JavaScript

const regex = /^[A-Za-z0-9+/]+={0,2}$/;
const test = "SGVsbG8gV29ybGQ=";
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+/]+={0,2}$'
test = "SGVsbG8gV29ybGQ="
match = re.search(pattern, test)
print(match)  # Found!

Go

package main

import (
    "fmt"
    "regexp"
)

func main() {
    re := regexp.MustCompile(`^[A-Za-z0-9+/]+={0,2}$`)
    fmt.Println(re.MatchString("SGVsbG8gV29ybGQ=")) // true
}

Common Use Cases

Data encoding validationAPI payloadsimage embedding

Match Examples

InputResult
SGVsbG8gV29ybGQ=Match
not base64!!!No Match

About the Base64 Encoded String Regex

Validates Base64-encoded strings with proper character set and optional padding. Used in data transfer and encoding.

Regular expressions (regex) are powerful pattern matching tools used across virtually all programming languages. The base64 encoded string pattern is classified as beginner 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 Base64 Encoded String regex pattern?

Validates Base64-encoded strings with proper character set and optional padding. Used in data transfer and encoding.

How do I use the Base64 Encoded String regex?

Use the pattern /^[A-Za-z0-9+/]+={0,2}$/ in your code. In JavaScript: new RegExp('^[A-Za-z0-9+/]+={0,2}$', ''). Test it above with your own input.

What does this Base64 Encoded String regex match?

This pattern matches: "SGVsbG8gV29ybGQ=". It does NOT match: "not base64!!!". Data encoding validation, API payloads, image embedding.

Is the Base64 Encoded String regex beginner-friendly?

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

What languages support the Base64 Encoded String 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 Base64 Encoded String 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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