Developer · free
JWT Decoder
Decode the header and payload of any JWT locally and check expiry. Your token never leaves the browser.
About the JWT Decoder
Decode the header and payload of any JWT locally and check expiry. Your token never leaves the browser.
Everything runs in your browser — nothing is uploaded.
How to use the JWT Decoder
- Step 1Paste your input into the field.
- Step 2Press the button to transform it.
- Step 3Copy or download the result.
When people reach for this tool
See what a token actually claims
The header and payload are base64url, so they can be read without any secret.
Confirm whether a token is already expired
The expiry claim is compared against the current time so you know whether it is still valid.
Compare the claims your code expects
A rejected token is often missing a claim or holding an unexpected value; seeing the payload settles it.
Practical tips
- Decoding proves nothing about authenticity. Only verifying the signature with the secret does that.
- Never paste a token you received from someone else into a tool you do not trust — treat any token as a credential.
What you get
- One-click transforms
- Local processing, nothing uploaded
- Free and unlimited
JWT Decoder — FAQ
Is the token sent anywhere?
No. Decoding is base64 splitting done locally; nothing leaves the browser.
Is a decoded JWT safe to share?
No. A token is a credential. Even though the contents can be read by anyone, the token itself should still be treated as a secret.
Why can I read a JWT without a key?
The header and payload are encoded rather than encrypted. Anyone can decode them, which is why nothing private should ever be put in a JWT payload.
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