ToolKun
CategoriesAbout Us
ToolKun

All-in-one online tool platform providing various useful tools to boost your productivity.

Quick Links

  • All Tools
  • Categories
  • Latest Tools
  • Tutorials

Support

  • Help Center
  • Contact Us
  • Feedback
  • About Us
  • Privacy Policy
  • Terms of Service
  • Sitemap
  • Gemini Watermark Remover

© 2026 ToolKun. All rights reserved.

Made with ❤️ for developers and creators

Base64 Encoder/Decoder Online

Online Base64 encoding and decoding tool, supports Unicode characters

Real-time conversion
Full Unicode support
One-click copy
Auto format detection

The Base64 encoder/decoder helps developers convert between binary data and text. Whether handling API authentication, embedding images, or debugging data transfer issues, this tool provides real-time conversion with full Unicode support, making encoding work simple and efficient.

What is Base64 Encoding?

Base64 is a method of converting binary data to printable ASCII characters. It uses 64 characters (A-Z, a-z, 0-9, + and /) to represent data, with = as padding. This encoding ensures data can be safely transmitted through text-only systems without special characters causing parsing errors.

Common Use Cases

  • Data URLs: Embed images directly in HTML or CSS, reducing HTTP requests and speeding up page loads.
  • API Authentication: HTTP Basic Authentication uses Base64 to encode username and password. JWT tokens also use Base64 encoding.
  • Email Transfer: MIME protocol uses Base64 to encode non-text attachments, ensuring email systems handle binary files correctly.
  • Storing Binary Data: Store images and files in text-only formats like JSON and XML.

Encoding Considerations

Base64 encoding increases data size by about 33%. For large files, this overhead can impact transfer efficiency. Base64 is NOT encryption - it provides no security protection. When handling non-ASCII text, the content must be converted to UTF-8 bytes before encoding. This tool handles this automatically.

FAQ

Q: How much larger does Base64 make data?

A: Base64 converts every 3 bytes into 4 characters, so encoded data is about 133% of original size (33% increase). This is because each Base64 character represents only 6 bits of data, while original bytes are 8 bits.

Q: Is Base64 secure? Can I use it to encrypt data?

A: Base64 is encoding, not encryption! Anyone can easily decode Base64 data. Its purpose is format conversion for transmission, not security. For protecting sensitive data, use encryption algorithms like AES or RSA.

Q: Why does my decoded text show garbled characters?

A: This usually happens when encoding and decoding use different character sets. Text should be UTF-8 encoded before Base64 encoding. This tool uses UTF-8 for all text processing, correctly handling all Unicode characters.