Base64 Encode / Decode
Convert text to Base64 and back. Auto-detects input format.
Quick test
Paste this to decode:
SGVsbG8gV29ybGQh→ "Hello World!"
Type this to encode:
Hello World!→ SGVsbG8gV29ybGQh
Common uses
Examples
| Text | Base64 |
|---|---|
| Hello World | SGVsbG8gV29ybGQ= |
| {"key":"value"} | eyJrZXkiOiJ2YWx1ZSJ9 |
| user:password | dXNlcjpwYXNzd29yZA== |
| 🚀 | 8J+agA== |
Data URL format
data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA...Prefix with data:[mime];base64, to embed in HTML/CSS.
FAQ
What is Base64 encoding?
Base64 is a way to represent binary data as ASCII text using 64 characters (A-Z, a-z, 0-9, +, /). It's used when you need to transmit binary data through text-only channels like email or JSON.
Why does Base64 increase file size?
Base64 uses 4 characters to represent every 3 bytes of data, resulting in ~33% size increase. This is the trade-off for being able to embed binary data in text formats.
What's the difference between Base64 and encryption?
Base64 is encoding, not encryption. Anyone can decode it — it provides no security. It's just a format conversion. Never use Base64 to "hide" sensitive data.
What is Base64URL?
Base64URL replaces + with - and / with _ to make the output URL-safe. JWTs use Base64URL encoding. This tool uses standard Base64.