JWT Encoder/Decoder - Free Online JSON Web Token Tool
Encode and Decode JSON Web Tokens (JWT) online. Create signed tokens with HS256 or inspect header, payload, and validate token structure.
Decode and inspect JSON Web Tokens (JWT) to view their header and payload.Perfect for debugging authentication tokens and understanding token structure.
- Decode JWT header and payload
- Format timestamps to readable dates
- Validate token structure
- Copy decoded data as JSON
- Client-side processing - tokens stay private
JWT Structure:
Header: Algorithm & token type
Payload: Claims/data (not encrypted)
Signature: Verifies token authenticity
About JWT Encoder/Decoder
Encode and Decode JSON Web Tokens (JWT) online. Create signed tokens with HS256 or inspect header, payload, and validate token structure. JWT Encoder/Decoder is a free online tool by NeXiilo — no sign-up required, and everything runs privately in your browser.
Whether you use it daily for work or occasionally for a quick task, JWT Encoder/Decoder gives you fast, accurate results without uploading your data anywhere.
How to Use JWT Encoder/Decoder
- Open the JWT Encoder/Decoder above — paste or enter your input.
- Adjust any options to match what you need.
- Get instant results right in your browser.
- Copy or reuse the output wherever you need it.
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Frequently Asked Questions
What is a JWT?
JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties. It is commonly used for authentication and information exchange in web applications.
What are the parts of a JWT?
A JWT consists of three parts separated by dots: Header (algorithm and token type), Payload (claims/data), and Signature (verification signature). All three are base64url encoded.
Can I decode a JWT without a secret key?
Yes, you can decode the header and payload without a secret key since they are only base64url encoded (not encrypted). However, you cannot verify the signature without the key.
Is it safe to decode JWTs online?
JWTs should not contain sensitive data in the payload since it is only base64 encoded (not encrypted). However, for maximum security, decode JWTs locally using trusted tools.
What is JWT used for?
JWTs are commonly used for user authentication, authorization, information exchange, and session management in modern web applications and APIs.