JSONToTable

Base64 URL Encoder

Encode text to URL-safe Base64 format (Base64url)

Text Input

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Base64url Output

URL-safe Base64 will appear here

Enter text in the input area to encode

About Base64 URL Encoder (Base64url)

Our Base64 URL Encoder converts text to URL-safe Base64 format (also known as Base64url), following RFC 4648 standard. This encoding replaces URL-unsafe characters (+, /, =) with URL-friendly alternatives (-, _, no padding), making it perfect for JWT tokens, OAuth flows, URL parameters, and filenames.

What is Base64 URL-Safe Encoding?

Standard Base64 encoding uses characters that have special meaning in URLs and filesystems (+, /, =). Base64url encoding solves this by using a URL-safe alphabet:

  • Standard Base64: Uses +,/, and = for padding
  • URL-safe Base64: Replaces + → -,/ → _, and removes = padding
  • Result: Safe to use in URLs, filenames, and HTTP headers without escaping

How to Use the Base64 URL Encoder

  1. Enter Text: Type or paste your text into the input area
  2. Automatic Encoding: See real-time URL-safe Base64 encoding as you type
  3. View Comparison: Compare standard Base64 vs URL-safe Base64 output
  4. Copy/Download: Use the Copy button for clipboard or Download for file
  5. Use in URLs: Safely embed the encoded string in URLs and APIs

Common Use Cases

  • JWT Tokens: JSON Web Tokens use Base64url for header and payload encoding
  • OAuth & SAML: Authentication protocols require URL-safe Base64 for state parameters
  • URL Parameters: Pass encoded data in query strings without escaping
  • Filenames: Create safe filenames from encoded data
  • HTTP Headers: Use in custom headers without special character issues
  • API Tokens: Generate URL-safe API keys and access tokens
  • Session IDs: Create web-safe session identifiers

Example: Standard vs URL-Safe Base64

Input Text:

Hello World! Testing +/= characters

Standard Base64 (NOT URL-safe):

SGVsbG8gV29ybGQhIFRlc3RpbmcgKy89IGNoYXJhY3RlcnM=

⚠️ Contains = padding, unsafe for URLs

URL-Safe Base64 (Base64url):

SGVsbG8gV29ybGQhIFRlc3RpbmcgKy89IGNoYXJhY3RlcnM

✓ No padding, safe for URLs and filenames

Features of Our Base64 URL Encoder

🚀 RFC 4648 Compliant

Follows official Base64url standard for maximum compatibility

🔄 Real-Time Encoding

Instant conversion as you type with live comparison view

🔍 Side-by-Side View

Compare standard Base64 and URL-safe Base64 simultaneously

🔒 Privacy First

All encoding happens locally in your browser - no server uploads

📋 Quick Copy

One-click copy to clipboard for immediate use

💾 File Support

Upload text files and download encoded results

JWT Token Example

JWT (JSON Web Token) uses Base64url for encoding its three parts:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9 (Header)
.
eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIn0 (Payload)
.
SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c (Signature)

Notice the use of _ (underscore) in the signature - this is URL-safe Base64 encoding in action!

Frequently Asked Questions

What is the difference between Base64 and Base64url?

Base64url is a URL-safe variant of Base64 that replaces + with -, / with _, and removes = padding. This makes it safe to use in URLs, filenames, and HTTP headers without additional encoding.

When should I use URL-safe Base64?

Use Base64url whenever your encoded data will appear in URLs (query parameters, path segments), JWT tokens, OAuth flows, filenames, or any context where +, /, and = characters could cause issues.

Is Base64url encoding reversible?

Yes! Base64url encoding is fully reversible. You can decode Base64url strings back to their original text using a Base64 URL decoder. The padding can be restored during decoding if needed.

Why is padding (=) removed in Base64url?

The = character has special meaning in URLs (query parameter separator). Removing padding makes the encoded string URL-safe. Decoders can calculate the correct padding based on the string length.

Can I use Base64url for JWT tokens?

Absolutely! JWT tokens specifically require Base64url encoding for their header and payload sections. This ensures tokens can be safely passed in HTTP headers and URL parameters.

Is Base64url more secure than regular Base64?

No, Base64url is not more secure - it's just URL-safe. Both Base64 and Base64url are encoding methods, not encryption. They don't provide security, only format conversion. Always use proper encryption for sensitive data.

What is RFC 4648?

RFC 4648 is the official standard that defines Base64, Base32, and Base16 encoding schemes, including the URL-safe Base64url variant. Our tool follows this standard for maximum compatibility.

Can I encode binary data with this tool?

This tool is optimized for text encoding. For binary data (images, files), you'll need to first convert the binary to a format that can be text-encoded, or use a tool specifically designed for binary Base64url encoding.

💡 Pro Tip

When implementing JWT authentication or OAuth flows, always use Base64url encoding for tokens and state parameters. Regular Base64 can break URLs due to special characters. Most JWT libraries handle this automatically, but understanding the difference helps debug encoding issues!

🔧 Developer Note

In JavaScript: Standard Base64 uses btoa(). For Base64url, apply replacements:btoa(str).replace(/\+/g, '-').replace(/\//g, '_').replace(/=/g, '')