Base64 Encoder / Decoder

What is Base64?

Base64 is a method of encoding binary data using a set of 64 printable ASCII characters. It's commonly used to encode data so that it can be transmitted over text-only channels, such as email or HTTP headers.

The name "Base64" comes from the fact that it uses 64 characters (A-Z, a-z, 0-9, +, /) to represent binary data. Every 3 bytes of binary data are converted to 4 characters in Base64.

Common Use Cases

• 📧
  Email Attachments: Binary files are Base64 encoded for email transmission
• 🔐
  Authentication: Basic HTTP authentication uses Base64 encoding
• 📊
  Data Serialization: Embedding binary data in JSON or XML documents
• 🖼️
  Image Embedding: Encoding images for use in data URIs or emails
• 🔗
  URL Safe: Encoding binary data for use in URLs

Base64 Character Set

Base64 uses 64 characters for encoding:

The equals sign (=) is used for padding to ensure the encoded string length is a multiple of 4.

How Base64 Works

1. Take binary input: Start with binary data or text characters
2. Group by 3 bytes: Divide the input into groups of 3 bytes (24 bits)
3. Split into 4 parts: Divide each 24-bit group into 4 parts of 6 bits each
4. Convert to decimal: Convert each 6-bit value to decimal (0-63)
5. Map to characters: Use the Base64 alphabet to map each value to a character
6. Add padding: Add equals signs if needed to make the result a multiple of 4

Encoding vs Decoding