Tech

Base64

Definition

A binary-to-text encoding scheme that converts binary data into a string of ASCII characters, commonly used for embedding data in web pages and emails.

Try the free calculator

Use our Base64 Encoder/Decoder to run the numbers yourself.

Base64 is an encoding method that represents binary data using 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). It is not encryption; it is simply a way to safely transmit binary data through systems designed to handle text.

Common uses of Base64 include embedding images directly in HTML or CSS (data URIs), encoding email attachments (MIME), transmitting binary data in JSON or XML, and encoding authentication credentials in HTTP headers.

Base64 encoding increases the data size by approximately 33%, since every 3 bytes of input become 4 bytes of output. While this overhead is acceptable for small files, it makes Base64 impractical for large binary data. URL-safe Base64 variants replace + and / with - and _ to avoid encoding issues in URLs.

Related Calculators

Related Terms

Related Articles

Stay Updated

Get notified about new tools, features, and exclusive deals. No spam, ever.