What is Base64 encoding?
Base64 is a binary-to-text encoding scheme that represents binary data in ASCII string format.
How Base64 Works:
Base64 encodes binary data using 64 different ASCII characters:
- Letters A-Z (uppercase)
- Letters a-z (lowercase)
- Digits 0-9
- Special characters + and /
- Padding character =
Why Use Base64?
- Data transmission: Safely transmit binary data over text-only protocols (email, JSON, XML)
- Embedding: Include images or files directly in HTML, CSS, or JSON
- API authentication: Encode credentials in HTTP Basic Authentication
- URL safety: Make binary data URL-safe (with Base64URL variant)
- Data storage: Store binary data in text-based databases or configuration files
Example:
Text: Hello World
Base64: SGVsbG8gV29ybGQ=
Important Notes:
- Base64 is NOT encryption - it's encoding for transport
- Encoded data is about 33% larger than the original
- Anyone can decode Base64 - never use it to hide secrets
- Use Base64URL variant for URLs (replaces + with -, / with , removes padding)
Common Use Cases:
- Encoding images as data URIs in CSS/HTML
- Transmitting binary files in JSON APIs
- Basic Authentication headers in HTTP requests
- Storing binary data in text-based formats
- Email attachments (MIME encoding)