Base64 Encoder & Decoder Online
Convert Text、Files or Images to Base64 Online - Supports Both Encoding and Decoding
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Understanding Base64 Encoding
Learn about Base64 encoding, its applications, and implementation in different environments.
What is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data in ASCII string format. It's commonly used to:
- Embed images in HTML/CSS/emails
- Send binary data in JSON payloads
- Transfer data in URLs safely
- Store binary data in databases
Browser Implementation
Modern browsers provide built-in methods for Base64 encoding/decoding:
// Encoding
const text = 'Hello, World!';
const encoded = btoa(text); // SGVsbG8sIFdvcmxkIQ==
// Decoding
const decoded = atob('SGVsbG8sIFdvcmxkIQ=='); // Hello, World!
// For Unicode strings
const encodedUnicode = btoa(unescape(encodeURIComponent(text)));
Data URI Scheme
Base64 is commonly used in Data URIs for embedding images in HTML/CSS:
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA..." />
/* Image as Base64 in CSS */
.logo {
background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAA...);
}
Important Notes
When working with Base64:
- Base64 encoded data is ~33% larger than the original
- Not suitable for large files in HTML (increases page load time)
- Use for small images/icons or when direct binary transfer isn't possible
- Always validate decoded data before using it in your application