Format guide
Base64
Base64 binary-to-text encoding (RFC 4648)
Base64 encodes any byte sequence as ASCII text using 64 printable characters (A-Z, a-z, 0-9, +, /, with = padding). Output is ~33% larger than input but survives every text channel that strips or mangles binary: email attachments (MIME), JSON fields, URLs (URL-safe variant), data: URIs, JWT payloads. The format dates to RFC 989 (1987) and was standardized in RFC 4648.
How to open a Base64 file
Any text editor displays base64. To decode back to bytes: `base64 -d` on Mac/Linux, `certutil -decode` on Windows, or paste into any base64 web decoder. Used heavily in dev tools, API debugging, and security workflows.
Primary use
Embedding binary data in text-only channels (email, JSON, URLs).
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