JWT Decoder
Decode JWT headers and payloads locally without verification.
Your input is processed locally in your browser. It is not saved, logged, or sent with analytics.
0 chars
Run: Ctrl/⌘ + Enter · Clear: Ctrl/⌘ + Shift + X
Decoded header and payload
Enter a value to begin.
What this calculator does
Inspect Base64URL JWT header and payload JSON locally; decoding does not verify signatures or claims.
Inputs and what they mean
- JWT
- — text value.
How to use it
- Paste or enter content in the editor.
- Adjust any options for the result you need.
- Copy or download the locally processed output.
Formula
Splits the token and Base64URL-decodes its JSON header and payload. The signature is not verified.
Worked example
Decode a sample structure
Inspect a token's header and payload without sending it anywhere.
Reading the result
The decoded header and payload appears in the output box and can be copied straight out. Nothing you paste leaves your browser.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.