Base64 Format Guide

About Base64 Format

Base64 is a binary-to-text encoding scheme defined in RFC 4648 that represents binary data using a set of 64 ASCII characters: uppercase letters (A-Z), lowercase letters (a-z), digits (0-9), plus (+), and forward slash (/), with equals sign (=) used for padding. Each group of three bytes is encoded as four Base64 characters, resulting in approximately 33% size increase.

Base64 encoding is essential in modern computing for safely transmitting binary data through text-based channels. It is used extensively in email attachments (MIME encoding), embedding images in HTML/CSS via data URIs, JSON Web Tokens (JWT), HTTP Basic Authentication headers, storing binary data in XML/JSON documents, and encoding cryptographic keys and certificates (PEM format).

Available Conversions

Base64 Format Features

• 64-Character Alphabet: A-Z, a-z, 0-9, +, / with = padding
• RFC 4648 Standard: Well-defined encoding specification
• URL-Safe Variant: Uses - and _ instead of + and /
• Data URIs: data:image/png;base64,... for inline embedding
• MIME Encoding: Standard for email attachment encoding
• JWT Tokens: Header and payload encoded in Base64URL
• PEM Certificates: SSL/TLS certificates stored as Base64

Common Uses

• Email: MIME encoding for attachments and non-ASCII content
• Web Development: Data URIs for inline images, fonts, and resources
• Authentication: HTTP Basic Auth, Bearer tokens, API keys
• Security: PEM certificates, cryptographic key encoding
• APIs: Encoding binary data in JSON/XML payloads
• Data Storage: Storing binary blobs in text-based databases
• Configuration: Encoding secrets in environment variables and config files