JWT Decoder

Free JWT decoder — paste your token to instantly decode header, payload, and signature. Works offline, no data sent to servers. Supports all JWT algorithms.

What this tool helps you do

JWT Decoder lets you enter the relevant details and get a clear result or breakdown in your browser. Use it to compare realistic scenarios before taking the next step.

How to use it

  1. Enter or select the details requested by the tool.
  2. Review the result, breakdown and any assumptions shown on the page.
  3. Change one value at a time to compare another scenario.

Accuracy, privacy and limitations

Most calculations run locally in your browser. Results are practical estimates, so confirm important figures with the relevant provider or authority before relying on them.