Base64 Encode/Decode — Complete Guide with Free Tool

Base64 turns binary data into text. It's everywhere — emails, APIs, data URIs, JWTs. Here's how it works.

What Is Base64?

Base64 encoding converts binary data into a string of 64 printable ASCII characters (A-Z, a-z, 0-9, +, /). The output is about 33% larger than the input but safe to transmit in text-only channels.

Encode/Decode Free

Use our Base64 Encoder/Decoder — paste text to encode, or paste Base64 to decode. Supports URL-safe mode and file-to-Base64 conversion via drag & drop.

Where Base64 Is Used

• Email attachments — MIME encoding for binary files
• Data URIs — Embed images directly in HTML/CSS: data:image/png;base64,...
• API authentication — HTTP Basic Auth uses Base64
• JWTs — JSON Web Tokens are Base64url encoded
• Storing binary in JSON/XML — Text-safe representation

Base64 vs URL-Safe Base64

Standard Base64 uses + and / which conflict with URLs. URL-safe Base64 replaces them with - and _ and removes trailing = padding.

In Code

• JavaScript: btoa('hello') / atob('aGVsbG8=')
• Python: base64.b64encode(b'hello')
• Bash: echo -n 'hello' | base64