JWT Decoder
Decode a JWT header and payload online for free, entirely in your browser.
How to use
- 1Paste a JWT into the box.
- 2View the decoded header and payload as formatted JSON.
Features
- Decodes header and payload
- Clearly states signature is not verified
- Runs entirely in your browser
Supported formats
Privacy
Your token is decoded locally in your browser and is never sent to our server. Signature verification is not performed.
About this tool
The JWT Decoder splits a JSON Web Token into its header and payload sections and decodes each from Base64URL into readable JSON. It does not verify the token's signature, so it should not be used to confirm that a token is authentic — only to inspect its contents.
Frequently asked questions
Does this verify the JWT signature?
No. This tool only decodes the header and payload — it does not verify the signature, since that requires the signing secret or public key.
Is it safe to paste a production JWT here?
Decoding happens entirely in your browser and the token is never sent anywhere, but as a general rule avoid pasting real production tokens into any website.
Why does decoding fail for my token?
A JWT must have exactly three dot-separated, Base64URL-encoded parts. If any part isn't valid JSON once decoded, decoding will fail.
Related tools
Base64 Encoder
Encode and decode Base64 text and data online, entirely in your browser.
JSON Formatter
Format and beautify JSON online with proper indentation, entirely in your browser.
JSON Validator
Validate JSON syntax and get clear error messages with line and column numbers.
JSON to CSV
Convert a JSON array of objects into a CSV file online for free.