Base64 Decoder

Free Online Base64 Decoder

Our Base64 Decoder is a free browser-based tool that instantly converts Base64 encoded strings back to their original text, JSON, HTML, or binary representation. Paste any Base64 string — from an API response, a JWT token, an email attachment, or a data URI — and get the decoded output in milliseconds.

All decoding is performed directly in your browser using JavaScript. Nothing is sent to any server, making this tool completely safe for decoding sensitive tokens, credentials, and private data. No account or login is required.

What is Base64 Encoding?

Base64 is a binary-to-text encoding scheme that represents binary data as a string of 64 printable ASCII characters: uppercase and lowercase letters (A–Z, a–z), digits (0–9), and the symbols + and /. The = character is used as padding.

It was designed to safely transmit binary data through systems that only handle text — such as email protocols (SMTP), HTTP headers, and JSON APIs. When you see a long string of letters and numbers ending with == or =, it is likely Base64 encoded.

Common Uses of Base64 Decoding

How to Use the Base64 Decoder

1. 1
   Paste the Base64 String

   Copy your Base64 encoded string from an API response, browser DevTools, JWT token, or any source and paste it into the input box.

2. 2
   Click Decode

   Press the Decode button. The original content appears instantly in the output area — plain text, JSON, HTML, or raw binary represented as readable characters.

3. 3
   Copy the Decoded Output

   Use the Copy button to copy the decoded string to your clipboard for use in your application, documentation, or debugging workflow.