JWT Decoder
Inspect JWT header, payload and expiry — tokens never leave the page.
This jwt decoder online lets you paste a JSON Web Token and read what is inside it. A JWT has three parts separated by dots: a header, a payload, and a signature. The tool decodes the header and payload so you can see the claims, such as the subject, issuer, and expiry time, without writing code. It is handy when you are debugging a login flow, checking why an API rejects a token, or confirming which scopes were issued. Because the decoding runs in your browser, the token is never sent to a server, which is important since real tokens can grant access to real accounts. Treat decoding as reading only: it shows the contents but does not by itself prove a token is trustworthy, since that needs the signing key. There is no upload, no account, and it works offline once loaded, so it is a simple jwt decoder tool when you do not want to use a CLI or script.
Frequently asked
Is it safe to paste my JWT into this decoder?
The decoding runs in your browser and nothing is uploaded. Still, avoid sharing live production tokens anywhere you do not need to.
Does the decoder verify the signature?
It reads the header and payload. Verifying a signature requires the secret or public key, so decoding alone does not prove a token is valid.
Does this JWT decoder work offline?
Yes. Once the page has loaded, decoding works without an internet connection.
Do I need Python or a CLI to decode a JWT?
No. Paste the token into the page and the claims are shown instantly, with no code or install.
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