📦 Base64 Encoder/Decoder

Encode text to Base64 or decode Base64 back to text — instantly in your browser.

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It is commonly used for embedding images in HTML, email attachments, and API authentication headers.

Common Use Cases

  • Email Attachments: MIME encoding uses Base64 to transmit binary data MIME encoding uses Base64 to embed binary files in text-based emails.
  • Data URLs: Embedding images directly in HTML/CSS Embedding images directly in HTML/CSS using data:image/png;base64,...
  • API Authentication: HTTP Basic Auth encodes credentials in Base64 HTTP Basic Auth encodes credentials in Base64.
  • JWT Tokens: JWT payloads are Base64URL encoded JWT payloads are Base64URL-encoded.

Converts data between binary and ASCII using Base64 encoding. Used for email attachments, data URLs, API payloads, and embedded images.

Key Facts

  • Increases data size by ~33%
  • Uses 64 characters: A-Z, a-z, 0-9, +, /
  • base64url variant uses - and _ for URL safety
  • = padding ensures output is multiple of 4

Frequently Asked Questions

What is Base64?

Binary-to-text encoding using 64-character alphabet. Ensures safe transmission through text-only channels.

Why use Base64?

For email attachments, data URLs, JSON binary data, and HTTP Basic Auth headers.

Is Base64 encryption?

No — it is encoding, not encryption. Anyone can decode it. Use AES/RSA for security.

Related Developer Tools

🔗 URL Encoder/Decoder 🎫 JWT Decoder 📋 JSON Formatter & Validator 🔐 Hash Generator