Base64 Encode / Decode
emptyEncode and decode Base64 strings. Supports UTF-8 and URL-safe Base64.
What is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It uses 64 characters (A-Z, a-z, 0-9, +, /) plus = for padding, resulting in output that's roughly 33% larger than the input.
Base64 is commonly used to embed binary data in JSON, XML, HTML, emails (MIME), data URIs, and HTTP headers. JWT tokens use a URL-safe variant that replaces + with - and / with _, and omits padding.
Fully supports UTF-8 input — including emoji and multibyte characters — by encoding the UTF-8 byte representation rather than raw code points. The URL-safe toggle switches between standard Base64 (RFC 4648 §4) and URL-safe Base64 (RFC 4648 §5).
Uses the native btoa() and atob() APIs. No data is ever sent to a server.