B64Base64 Encode/Decode
Encode or decode Base64 strings
Base64 Encoder/Decoder Complete Guide
Base64 encodes binary data using 64 ASCII characters. Introduced as part of MIME in 1987, it's widely used today for email attachments, image Data URIs, JWT tokens, HTTP Basic Auth — anywhere binary data needs to traverse text-only systems safely.
Key Features
- Encode/Decode: Bidirectional text ↔ Base64 conversion
- UTF-8 Handling: Safely converts Korean, emoji, non-ASCII
- URL-safe Option: JWT/OAuth-friendly format
- File Upload: Instantly convert images/PDFs to Data URIs
- Size Stats: Input/output bytes + compression ratio
Use Cases
| Purpose | Example |
|---|---|
| HTTP Basic Auth | Authorization: Basic dXNlcjpwYXNz |
| JWT Tokens | eyJhbGciOiJIUzI1NiJ9... (URL-safe) |
| Image Embedding | <img src="data:image/png;base64,..." /> |
| Email Attachments (MIME) | Binary files → Base64 over SMTP |
| CSS Font Embedding | @font-face url(data:font/woff2;base64,...) |
Base64 Character Set
Standard: A-Z (0-25), a-z (26-51), 0-9 (52-61), + (62), / (63), = (padding)
URL-safe: + → -, / → _, = removed