Decode and inspect JSON Web Token payload and header

JWT Token
Decoded Header & Payload

How to Use This Tool

1

Enter your input

Paste or type the text, URL, or data you want to encode or decode into the input panel on the left.

2

Instant result

The encoded or decoded output appears immediately in the right panel without any delay.

3

Copy the result

Click the "Copy" button to copy the output to your clipboard, ready to use in your code or application.

4

Download if needed

For longer outputs, use the Download button to save the result as a text file.

About This Tool

JWT Decoder is a free, instant, browser-based tool that decode and inspect json web token payload and header. Encoding and decoding are essential operations in modern software development. Whether you're working with APIs, building authentication systems, handling URLs, processing file uploads, or debugging data pipelines, you'll constantly encounter the need to encode or decode data in various formats.

This tool runs entirely in your browser using standard Web APIs and JavaScript. No data is ever transmitted to a server, making it safe to use with sensitive content. There are no usage limits and no sign-up required.

Encodings like Base64 are used extensively in HTTP Basic Auth headers, data URIs for embedding images in HTML and CSS, JSON Web Tokens, email attachments (MIME), and binary data transmission over text-based protocols. URL encoding is required whenever you include special characters in query strings or path segments. HTML entity encoding prevents XSS vulnerabilities by escaping characters that have special meaning in HTML.

Understanding encodings is also critical for debugging — many data corruption issues in web applications trace back to double-encoding, missing decoding steps, or character set mismatches. This tool lets you quickly check what an encoded string actually contains, or verify that your encoding logic produces the expected output.

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