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Browser-only JWT decoding

JWT Decoder

Decode JWT header and payload data online. Inspect claims such as algorithm, issuer, audience, subject, expiry and issued-at timestamps locally in your browser.

Decode JWT Token

Header

Algorithm and token metadata

{}

Payload

Claims and application data

{}
Important: decoding a JWT does not verify its signature or prove that its claims are trustworthy. Signature, issuer, audience, expiry and application-specific validation must be performed by the consuming application.

About JWT Decoder – Decode JWT Tokens Online

The JWT inspector splits a three-segment compact token, decodes the Base64URL header and payload as UTF-8, and parses both as JSON.

Input is processed locally in your browser and is not sent to Navorika.

How the calculation works

JWT structure

Base64URL(header).Base64URL(payload).signature.

Inspection only

Decoding reveals claim text but performs no cryptographic signature validation.

How to use this tool

  1. 1Paste a compact three-part JWT.
  2. 2Review the formatted header and payload.
  3. 3Treat every displayed value as untrusted until a trusted server verifies signature, issuer, audience, expiry, and application rules.

Understanding the result

The alg field is merely token-supplied data and must not be trusted by itself.

Claims such as exp, iss, aud, sub, and roles are assertions, not proof, until verification succeeds.

Important limitations

  • This tool does not verify signatures, keys, algorithms, issuer, audience, expiry, not-before time, nonce, or revocation.
  • Do not paste production access tokens into tools you do not trust, even when processing is described as local.
  • Only JWTs whose first two segments decode to valid UTF-8 JSON are displayed.
  • The included Base64 tab uses standard Base64, not Base64URL.

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Frequently asked questions

Does successful decoding mean a JWT is valid?

No. Anyone can construct decodable header and payload segments.

Is the signature verified?

No.

Are Unicode claims supported?

Yes. Segments are decoded as UTF-8.

Is the token uploaded?

No.

Use with

These tools support a practical next or previous step in the same workflow.

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