Decode JWT Payloads | JSON Web Token Viewer
Instantly decode JSON Web Tokens (JWT) to inspect headers and claims. This tool provides a fast, client-side way to view token contents without requiring signature verification—perfect for debugging authentication flows.
💡 Why Use This?
Stop guessing what’s inside your Base64 strings. Use this viewer to:
- Verify Claims: Check user roles, permissions, or custom metadata.
- Troubleshoot Expiry: Instantly see if a token has expired or if the iat (issued at) time is correct.
- Inspect Headers: Confirm the algorithm (alg) and token type (typ) match your server configuration.
📘 Features
- Instant Decoding: Paste any
header.payload.signaturetoken to see the formatted JSON immediately. - Human-Readable Timestamps: Automatically converts Unix timestamps like
exp,iat, andnbfinto your local date and time. 🗓️ - Pretty Print: Automatically indents and color-codes JSON for better readability. ⚡
- Privacy First: All processing happens locally in your browser. Your tokens are never sent to a server, keeping your sensitive data private. 🛡️
🧐 Frequently Asked Questions
- Does this tool verify signatures?
- No. This is a viewer, not a validator. It displays the content regardless of whether the signature is valid. For security testing, use a tool that supports secret/public key verification.
- Is it safe for production tokens?
- Yes. Because the decoding logic runs entirely on the client side, your data stays in your browser. However, always exercise caution when handling production tokens in any web-based environment.
- Why is my token not decoding?
- Ensure the token follows the standard format of three Base64Url strings separated by periods (
.). Note: This tool does not support encrypted tokens (JWE).
⚠️ Security Reminder
In the industry, "JWT" is often pronounced like the word "jot."
Remember: standard JWTs are signed, not encrypted. This means anyone with the token can read its contents using a tool like this. The signature only proves the data hasn't been tampered with. Never store sensitive information like passwords, API keys, or credit card numbers in a JWT payload.