JWT Decoder

Decode JSON Web Tokens and inspect claims

🔒 100% in-browser🆓 Free forever⚡ No sign-up

JWT token

How it works

1
Paste your JWT
Drop the token (header.payload.signature) into the input box.
2
Inspect the header and payload
The three base64url segments are decoded and formatted as JSON.
3
Check the claims
Standard claims like exp, iat, nbf are shown with human-readable dates and an expired/valid badge.

About JWT Decoder

Free online JWT decoder. Paste any JSON Web Token to decode the header, payload, and signature. See standard claims (iss, sub, exp, iat) formatted with human-readable timestamps and an expiry indicator. All decoding happens in your browser. JWT Decoder on 712 Tools runs entirely inside your browser using modern JavaScript APIs — no server ever sees your data. That means instant results, complete privacy, and no upload limits.

Whether you need to decode json web tokens and inspect claims for a debugging session, a quick sanity check, or a production incident, this tool is free to use as many times as you need. There are no watermarks, no sign-up, and no ads inside the tool itself.

Frequently asked questions

Does it verify the signature?

No. This tool only decodes the token — verifying signatures requires the secret or public key, which should never be pasted into a public web tool.

Is my token uploaded?

Never. All base64url decoding happens locally in your browser. Nothing is stored, logged, or sent.

Is it safe to paste production tokens?

Because decoding happens locally, yes — no network request is made. Still, treat any browser tool with care and prefer a local CLI for the most sensitive tokens.

What algorithms are supported?

The header shows any 'alg' value. Decoding is algorithm-independent since it only parses the base64url segments.

6 min read

JWT explained: what actually goes inside that token

Every login flow you touch these days involves JWTs, but 'JSON Web Token' hides a lot. Here's the three-part structure, the security pitfalls, and when not to use them.

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