Base64 Encode
Operation Mode
Input Plain Text/File
Output Base64
Options
Uses A-Z, a-z, 0-9, +, / and = padding
Automatically convert when input changes
Base64 Encoding Reference (Click to expand)
Base64 Alphabet
| Variant | Characters Used | Padding |
|---|---|---|
| Standard | A-Z a-z 0-9 + / |
= |
| URL-safe | A-Z a-z 0-9 - _ |
None |
| MIME | A-Z a-z 0-9 + / |
= + line breaks |
When to Use
- Standard For general encoding, data storage
- URL-safe For URLs, filenames, JWT tokens
- MIME For email attachments, legacy systems
Base64 encoding increases data size by approximately 33%. Every 3 bytes of input become 4 characters of output.