What is Base64?

Learn about Base64 encoding: how it works, why it's used, and its applications in modern web development.

Base64 Definition

Base64 is a binary-to-text encoding scheme that converts binary data into a string of ASCII characters. It uses 64 different characters (A-Z, a-z, 0-9, +, /) to represent data, making it safe for transmission over text-based protocols like HTTP, email, and JSON.

Original text: "Hello World!"
Base64 encoded: SGVsbG8gV29ybGQh

Text Safe

Converts binary data to safe ASCII text format

Web Compatible

Works in URLs, JSON, XML and web protocols

Universal Standard

Supported by all programming languages and platforms

How Base64 Works
The encoding process explained step by step

1. Binary Data

Input data is converted to binary representation (8-bit bytes)

2. Group in 6-bits

Binary data is divided into 6-bit groups (64 possible values)

3. Map to Characters

Each 6-bit value maps to one of 64 ASCII characters

Base64 Character Set:

A-Z: Values 0-25
a-z: Values 26-51
0-9: Values 52-61
+ /: Values 62-63
=: Padding character
Common Use Cases
Where Base64 encoding is commonly used in web development

Email Attachments

Encode binary files in email messages (MIME)

PDF, images, documents in email

Web APIs

Send binary data through JSON REST APIs

Image uploads, file transfers via API

Data URLs

Embed images directly in HTML/CSS

data:image/png;base64,iVBORw0KGgoA...

Configuration Files

Store binary data in text-based config files

Certificates, keys in YAML/JSON
Advantages
  • Safe for text-based transmission
  • Universally supported
  • No special characters in output
  • Preserves binary data integrity
Limitations
  • 33% size increase over binary
  • Not suitable for large files
  • Encoding/decoding overhead
  • Not human-readable
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