Ad
INPUT TEXT
ENCODED OUTPUT
Common use cases
- Encode credentials for HTTP Basic Authentication
- Decode JWT payloads to inspect their content
- Embed binary data in CSS or HTML data URIs
- Apply or reverse classical ciphers (ROT13, Caesar)
Frequently asked questions
Is Base64 encryption?
No. Base64 is encoding — easily reversible by anyone. For real encryption use AES.
Why does Base64 increase size?
Base64 represents 3 bytes of data using 4 ASCII characters, adding ~33% size overhead.
What is Base64URL?
A URL-safe Base64 variant that uses - and _ instead of + and / so the encoded value can appear in URLs without escaping. Used in JWT tokens.