Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text - instant, client-side.
About this tool
Base64 encodes binary data as ASCII text using 64 printable characters (A–Z, a–z, 0–9, +, /). It's widely used in JWTs, embedding images in CSS/HTML via data URIs, email attachments (MIME), and HTTP Basic Auth headers. Every 3 bytes of input become 4 Base64 characters - roughly a 33% size increase. This tool handles full Unicode input correctly by UTF-8 encoding before encoding to Base64.