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Base64 Encoder/Decoder

Convert text to Base64 encoding and decode Base64 strings back to readable text. All processing happens locally in your browser for maximum privacy and security.

Privacy FirstNo Server Required

Conversion Mode

Text to Encode

Common Use Cases

Encoding

  • • Embedding images in HTML/CSS
  • • Storing binary data in JSON
  • • Email attachments (MIME)
  • • URL-safe data transmission

Decoding

  • • Extracting embedded file data
  • • Processing API responses
  • • Reading encoded configuration
  • • Analyzing Base64 content

About Base64 Encoding

What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation using 64 printable characters.

Character Set

Base64 uses 64 characters: A-Z (26), a-z (26), 0-9 (10), plus (+) and slash (/), with equals (=) used for padding.

Common Applications

  • • Email attachments (MIME encoding)
  • • Embedding images in HTML/CSS
  • • Storing binary data in JSON/XML
  • • HTTP Basic Authentication
  • • Data URLs and web APIs

Size Impact

Base64 encoding increases data size by approximately 33% due to the encoding overhead. Every 3 bytes of binary data becomes 4 characters of Base64 text.

💡 Pro Tips

  • • Base64 is encoding, not encryption - it provides no security
  • • Padding with = characters ensures proper length alignment
  • • URL-safe Base64 uses - and _ instead of + and / for web compatibility
  • • Always validate decoded data for expected content and format