Tools

JWT Decoder - Decode free JSON Web Tokens online

Easily decode JWTs and view payload content with our free online JWT Decoder. Perfect for developers, programmers and security specialists who want to analyze tokens.

Encoded Token

Decoded Token

Header

Payload

What is a JSON Web Token (JWT)?

A JSON Web Token (JWT) is a compact and secure method for exchanging information between two parties. These tokens are widely used in modern authentication systems, where they are issued after a user logs in to confirm their identity. The JWT acts as a digital passport: it is small, contains relevant claims about the user, and can be sent with every request to access secure resources.

The three parts of a JWT

A JWT is composed of three parts, separated by a period (`.`), each serving a specific purpose:

Header: Contains metadata about the token, such as the token type (`JWT`) and the encryption algorithm (`HS256`, `RS256`, etc.) used to create the signature.
Payload: This is the heart of the token. The payload contains the "claims"—statements about the entity (usually the user) and additional data. This can include a user ID, name, roles, or the token's expiration date.
Signature: This is the cryptographic signature. It is calculated based on the header, the payload, and a secret key known only to the server. The signature guarantees the token's integrity; if the token has been tampered with, the signature will be invalid.

How to use our free JWT Decoder?

Our JWT Decoder is an indispensable online tool for developers, programmers and security specialists. You can quickly view the contents of a token and analyze the claims without manual decoding. Follow these steps:

Paste your token: Copy the full JWT string and paste it into the input box.
View the contents: The tool automatically splits the token and decodes the Base64-encoded header and payload.
Analyze the data: You will get a clear, formatted view of the JSON data. This makes it easy to debug, verify, or inspect claims.

Important note: This tool only decodes the public, Base64-encoded parts of the JWT. The signature is not verified or validated. Therefore, use this tool only for educational purposes or for inspecting tokens whose origin you trust.

Frequently Asked Questions about JWT

Here we answer some frequently asked questions to help you get the most out of this tool:

Can this tool reveal the secret key?

No, the secret key is only used to create the signature on the server side. It is never stored in the token itself and cannot be derived from the public parts.

What is the difference between JWT and a session cookie?

Session cookies require the server to maintain the user's state (stateful). JWT is stateless: the token contains all the necessary information and the server does not have to store a session, which makes it ideal for scalable, distributed systems.

Fun Facts about JSON Web Tokens

JWT is an open standard (RFC 7519) supported by almost all programming languages and frameworks.
The use of JWT has largely replaced traditional session management methods for APIs and microservices.
Although the data in the payload is not visible to the user, it is not encrypted. Therefore, never store sensitive information, such as passwords, in the payload of a JWT.

FAQ

How are the files processed?

Your privacy and security are our top priority. Files are deleted from our servers immediately after processing. We do not store your files.

Is the website safe to use?

Yes, our website is fully secured with SSL encryption to ensure that all of your data is transmitted safely.

Are there costs associated with the service?

There are no costs associated to the services we deliver. Everything is free and has unlimited access

Which file formats are supported?

We support a wide range of file formats, including PDF, DOC, DOCX, XLSX, JPG, PNG, and more. You can find the full list on our website.

Why are my conversions taking so long?

The duration of a conversion can vary. Complex tasks require more processing time to ensure the best quality. A slow internet connection can also affect upload speed.

Is an API available?

Currently, there is no public API available. We are working on the possibilities of offering an API in the future.