Base64 Encoding and Decoding

Base64 is a binary-to-text encoding scheme that converts binary data into ASCII string format. It's commonly used to encode data that needs to be transmitted over media designed to handle text, such as email or URLs. Our free Base64 encoder and decoder makes it easy to convert data in both directions.

What is Base64 Encoding?

Base64 encoding uses 64 different characters (A-Z, a-z, 0-9, +, /) to represent binary data. Every 3 bytes of binary data are converted to 4 Base64 characters. If the data isn't a multiple of 3 bytes, padding characters (=) are added at the end.

Common Uses for Base64

• Email Attachments: Encoding binary files for transmission via email
• Data URLs: Embedding images directly in HTML or CSS
• API Requests: Sending binary data in JSON payloads
• Basic Authentication: Encoding credentials for HTTP headers
• Storing Binary Data: Saving binary data in text-based formats like JSON or XML

How Base64 Works

The encoding process takes binary data and splits it into 6-bit chunks. Each chunk is then mapped to one of the 64 characters in the Base64 alphabet. For example, the text "Hello" becomes "SGVsbG8=".

Base64 vs Other Encodings

• Base64: 64 characters, 33% overhead, most common
• Base32: 32 characters, 40% overhead, case-insensitive
• Hexadecimal: 16 characters, 100% overhead, human-readable
• URL-Safe Base64: Uses - and _ instead of + and /

When to Use Base64

Use Base64 when you need to transmit binary data through text-based systems or protocols. It's perfect for embedding small images in HTML, sending files through APIs, or encoding credentials for authentication headers.

Base64 Security Considerations

Important: Base64 is encoding, not encryption. Anyone can decode Base64 data without a key. Never use Base64 alone to protect sensitive information. Always combine it with proper encryption methods like AES or RSA when security is required.