Security Notice
This tool only decodes the JWT so you can view its contents. It does not verify the cryptographic signature or validate the token's authenticity. Never trust a JWT from an unverified source.
Understanding JSON Web Tokens (JWT)
JSON Web Tokens are the bedrock of modern stateless authentication. They are used to transmit information between parties as a compact, URL-safe JSON object. This information can be verified and trusted because it is digitally signed. Toolvado's JWT Decoder allows you to strip away the Base64Url encoding to see exactly what data is being carried by your bearer tokens.
Technical Breakdown
A standard JWT consists of three parts separated by dots: Header.Payload.Signature. Our tool extracts and formats the first two, providing a readable view of your token's metadata and claims.
Header Decoding
View the signing algorithm (e.g., HS256, RS256) and token type to ensure your identity provider is configured correctly.
Payload Claims
Inspect user IDs, roles, permissions, and custom claims. Verify if the exp (expiration) and iat (issued at) times are accurate.
Secure Debugging
Perform your audits entirely client-side. Your production tokens and sensitive user information never touch our infrastructure.
Why Developers Use Our JWT Inspector
"Is my token expired?"
Authentication issues are often caused by misconfigured expiration times. Use our decoder to check the exp claim and verify it against current Unix timestamps. This is the first step in troubleshooting 401 Unauthorized errors.
"Does it have the right scopes?"
Granular permission systems rely on the scope or roles claims within the token. Our formatter makes it easy to scan list structures and ensure your users have the access they need.
Privacy is Not Optional
JWTs are effectively keys to your application. Sending them to a third-party server for "decoding" is a massive security risk. At Toolvado, we utilize local Javascript processing so your secrets remain secrets.
JWT Decoding FAQ
Q: What do the three dots in a JWT mean?
The dots are separators. A JWT is structured as [Header].[Payload].[Signature]. Each part is Base64Url encoded separately. Our tool extracts and decodes the first two sections for inspection.
Q: Can I use this tool to verify a JWT signature?
No. This tool is a decoder only. Signature verification requires the secret key or certificate used to sign the token, which should never be shared with online tools. Use our decoder to view claims, but use your official backend libraries for verification.
Q: What encryption does JWT use?
JWTs are typically signed, not encrypted (using JWS). This means the data is readable by anyone who decodes it, but it cannot be tampered with. If you need hidden data, look into JSON Web Encryption (JWE).
Q: Is it safe to use this decoder for sensitive production tokens?
Yes. Toolvado's architecture ensures that the decoding logic runs within your own browser sandbox. No data is ever transmitted to 'the cloud' or our analytics systems.
100% Private & Secure
All processing happens locally in your browser. No data is stored or sent to servers.