What Is Base64 Encoding and When Should You Use It?

Base64 turns binary data into safe, text-friendly characters. Learn what it is, how it works, when to use it, and when not to, plus a free encoder and decoder.

Base64 is a way of representing binary data like an image or a file using only 64 plain text characters. It is everywhere in web development, from data URLs to email attachments and API tokens.

Why Base64 exists

Some systems, such as older email protocols and URLs, were designed to handle text, not raw binary. Base64 encodes binary into safe letters, numbers and symbols so it can travel through those text-only channels without being corrupted.

How it works, briefly

Base64 takes three bytes of data and represents them as four text characters. That is why encoded data is about a third larger than the original, a trade-off for safe transport.

When to use it and when not to

• Good uses: embedding small images in CSS/HTML, encoding data for URLs, or storing binary in text fields.
• Avoid for: large files and security. Base64 is encoding, not encryption. Anyone can decode it.

Encode and decode for free

Use the free Base64 Encoder/Decoder to convert text and data both ways in your browser. For working with encoded API responses, pair it with the JSON Formatter.