Paste Token
Decoded Header
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Decoded Payload
No payload claims available.
About the JWT Decoder
A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is digitally signed using JSON Web Signature (JWS).
Our Online JWT Decoder allows you to disassemble any JWT into its component parts: the header, the payload, and the signature. It provides a visual, color-coded structure maps the raw base64url string back to formatted JSON outputs.
The tool runs entirely in your web browser. All cryptographic signature verifications and Base64URL translating run on your device utilizing standard browser APIs. None of your data, secrets, or certificates are uploaded, keeping your debugging private.
How to Use the Online JWT Decoder
Paste Encoded JWT
Copy and paste any signed or unsigned JSON Web Token (JWT) into the input area.
Inspect Header & Payload
View base64URL decoded JSON objects instantly. Color-coded markers guide you to each segment.
Analyze Claims & Timestamps
Verify standard claims like exp, iat, and nbf translated automatically into local and UTC dates.
Verify Signature Cryptography
Enter your HMAC secret or paste an RSA Public Key PEM to run client-side signature verification.
Common Use Cases
Debugging Token Authentication: Quickly inspect token claims, user roles, and expiration details when API authentication fails.
Integrity & Trust Checks: Confirm if a client token was signed with the correct secret or private key without deploying code.
Verifying Token Life Cycle: Check if a token has expired or is not yet active (nbf) due to clock skew or timestamp mismatches.
Format Validation: Identify if client-side libraries are formatting header parameters (alg, typ) or payload variables correctly.
Developer Learning & Education: Explore the internal components of a JSON Web Token and visualize how cryptographic signatures are verified.
Why Choose Our JWT Decoder
100% Browser-Based Security
No keys, secrets, or payloads are ever uploaded. All decodings and signatures are processed locally.
HMAC & RSA Signature Verification
Supports HS256/384/512 symmetric secrets and RS256/384/512 public keys in PEM formats.
Smart Expiration & Clock Analyzer
Computes if the token is valid, active, or expired, indicating time differences in human terms.
Color-Coded Dual-Pane Explorer
Highlight blocks interactively. Clear visual feedback guides you from raw string segments to decoded values.
JSON Syntax Validation & Prettify
Detects malformed payloads or headers immediately and displays pretty-printed nested structures.
Instant Copy Helpers
Copy individual segments, decoded JSON, or verification results with one-click clipboard shortcuts.