Base64 Encoder/Decoder

Convert text and data to Base64 encoding and back. Essential for web development, APIs, data URIs, and authentication tokens. Instant, accurate, and free.

Base64 Encoder/Decoder

What is Base64?

Base64 is an encoding scheme that converts binary data into ASCII text format using 64 characters (A-Z, a-z, 0-9, +, /). It's used to safely transmit binary data over text-based protocols like email, JSON, or URLs.

Common Use Cases

🔐 API Authentication: Basic Auth headers encode credentials as Base64: Authorization: Basic dXNlcjpwYXNz
🖼️ Data URIs: Embed images in HTML/CSS: data:image/png;base64,iVBOR...
📧 Email Attachments: MIME encodes attachments as Base64 for transmission
🔑 JWT Tokens: JSON Web Tokens use Base64URL encoding for header and payload

Example

Original: Hello World!

Base64: SGVsbG8gV29ybGQh

FAQ

Is Base64 encryption?

No! Base64 is encoding, not encryption. It's easily reversible and provides no security. Don't use it to hide sensitive data — use proper encryption instead.

Why does Base64 increase file size?

Base64 increases size by ~33% because it represents 3 bytes of binary data using 4 ASCII characters. This overhead is the cost of text-safe transmission.

What are the = signs at the end?

The = signs are padding to make the output length a multiple of 4. They're required by the Base64 specification and indicate how many bytes the original data had.