Does this verify the JWT signature?

No. It only base64url-decodes the header and payload for inspection. Signature verification needs the signing secret or public key on a trusted backend.

Is pasting a JWT safe here?

Processing is local. Still avoid pasting production tokens with sensitive claims into any shared screen or recording.

JWT Decoder

Free online JWT decoder to inspect header and payload. Does not verify signatures. Fully client-side.

Processed locally in your browser — nothing is uploaded.

Decodes header and payload only — signature is not verified.

JWT

Header

{
  "alg": "HS256",
  "typ": "JWT"
}

Payload

{
  "sub": "1234567890",
  "name": "DevTools",
  "iat": 1516239022
}

Signature

SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

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About this tool

Inspect JSON Web Token headers and payloads instantly. This decoder does not verify signatures—use it for debugging claims, expiry, and structure. Everything stays in your browser.

Frequently asked questions

Does this verify the JWT signature?: No. It only base64url-decodes the header and payload for inspection. Signature verification needs the signing secret or public key on a trusted backend.
Is pasting a JWT safe here?: Processing is local. Still avoid pasting production tokens with sensitive claims into any shared screen or recording.