Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 strings. All processing happens locally in your browser.

Text to Encode

Characters: 0

Base64 Output

Characters: 0
About Base64 Encoder/Decoder & Technical Guide

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It works by dividing every three bits of binary data into four 6-bit units. These units are then mapped to a set of 64 characters (A-Z, a-z, 0-9, and symbols like + and /).

The primary purpose of a Base64 Encoder is to ensure that binary data can be transmitted over media that only support text-based formats (like email bodies or URL parameters) without getting corrupted.

Common Applications of Base64

  • Data Transmission: Embedding images or other binary files directly into HTML or CSS files using "Data URIs".
  • Authentication: Basic Auth headers use Base64 to encode the "username:password" pair.
  • JWTs: JSON Web Tokens use Base64Url encoding for their headers and payloads.
  • Safe URLs: Converting potentially breaking characters into a URL-safe string format for query parameters.

Important: Encoding is NOT Encryption

A common security misconception is that Base64 "hides" data. Base64 is an encoding scheme, not encryption or hashing. Anyone can decode a Base64 string instantly without a key. Never use Base64 to protect sensitive secrets without layered encryption.

Base64 Technical FAQ

What does the '=' at the end of some Base64 strings mean?

This is called "Padding." Since Base64 processes data in 24-bit chunks (three 8-bit bytes), it needs padding characters if the input data doesn't perfectly divide by three. The '=' character ensures the resulting string length is always a multiple of four.

Why does my Base64 output look different for "Hello"?

Encoding results can differ based on character encoding (UTF-8 vs UTF-16). Our tool uses standard UTF-8 processing to ensure maximum compatibility with modern web APIs.

🔒 Privacy Commitment

Like all tools in the Dev Tool Kit, this Base64 Encoder/Decoder operates 100% client-side. Your data is processed locally in your browser and is never sent to our servers. Privacy is not just a feature; it's our core architecture.