Base64 Encoder & Decoder
Encode plain text to Base64 or decode Base64 back to plain text with optional URL-safe encoding. Fast, free, and fully client-side. Nothing is uploaded to a server.
Input
0 chars · 0 wordsOutput
0 charsHow the Base64 Encoder & Decoder Works
Encodes binary and text data into ASCII characters using the Base64 representation standard (RFC 4648). Widely used in data URIs, email MIME attachments, and API authentication headers.
Usage Example
Encoding "Hello World" → "SGVsbG8gV29ybGQ=" | Decoding "SGVsbG8gV29ybGQ=" → "Hello World".
Frequently Asked Questions
What is URL-safe Base64?
URL-safe Base64 replaces "+" with "-" and "/" with "_" so the string can be safely passed in URL query parameters without percent-encoding.
Why does Base64 output end with = symbols?
The "=" characters are padding bytes added when the input byte length is not evenly divisible by 3.