Base64 Calculator

Encode text to Base64 or decode Base64 back to text.

Base64 Output
Input Characters
0
Output Characters
0
Input Bytes
0
Size Ratio

Validation

How Base64 Works

Base64 Encoding

Base64 encodes binary data into an ASCII string using 64 characters (A-Z, a-z, 0-9, +, /). It increases size by about 33% but ensures safe transmission over text-based protocols.

Every 3 bytes of input become 4 Base64 characters

Padding character '=' is used when input length isn't a multiple of 3

Common Uses

  • Email attachments (MIME encoding)
  • Embedding images in HTML/CSS (data URIs)
  • API authentication tokens
  • Encoding binary data in JSON

Related Calculators