What Is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's widely used for email attachments (MIME), embedding images in HTML/CSS as data URLs, and encoding credentials in HTTP Basic Auth headers. Base64 increases data size by approximately 33%.
How to Use
Paste text into the input area and click "Encode to Base64" to convert it. To reverse the process, paste a Base64 string and click "Decode from Base64". The tool supports UTF-8 characters including Chinese text, emoji, and special symbols.
Usage Example
Encoding:
Input: Hello World! Output: SGVsbG8gV29ybGQh
Decoding:
Input: SGVsbG8gV29ybGQh Output: Hello World!
Important Note
Base64 is encoding, not encryption. Anyone can decode Base64 without a key. Do not use Base64 to protect sensitive data — use proper encryption algorithms (AES, RSA) instead. Base64 is designed for data transport, not security.
Frequently Asked Questions
Base64 converts 3 bytes of binary data into 4 ASCII characters, resulting in a ~33% size increase. This is the trade-off for making binary data safe to transmit in text-only protocols.
Yes. Most programming languages have built-in Base64 functions: JavaScript has btoa()/atob(), Python has base64 module, and you can use atob/atob in browser dev tools.