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What Is Base64 and When to Use It

Base64 turns binary data into plain text. It shows up in emails, web pages and APIs — here’s what it actually does and when it makes sense.

What Base64 does

It represents any data using 64 safe characters (A–Z, a–z, 0–9, + and /). This lets binary files — images, attachments — travel through systems that only handle text, without getting corrupted.

Where you’ll see it

Email attachments, data URLs in CSS/HTML (like embedded images), JSON Web Tokens and many APIs use Base64. The Base64 Encode and Decode tools convert text both ways.

What it is NOT

Base64 is not encryption or compression. It’s easily reversed and actually makes data about 33% larger, so never use it to hide secrets — use it only to move binary data safely as text.

Related tools

Last updated: July 6, 2026