JWT Decoder
Decode JWT tokens fast — header, payload, and claims (iat/exp/nbf) shown human-readable. Runs 100% in your browser, token never leaves your device.
Header
Payload
What is a JWT?
A JSON Web Token is the standard format for transmitting claims between client and server (auth, API access). Three parts:
<header>.<payload>.<signature>Security note
- This tool only decodes — it does NOT verify the signature. The payload is shown even if the signature is invalid.
- Never paste production JWTs containing sensitive data into any online decoder — including this one. Use dev/test tokens.
- Decoding runs 100% in your browser. Disconnect from the internet → it still works.
Who this is for
Backend devs, API integrators, anyone debugging JSON/YAML/CSV payloads or working with structured data.
FAQ
Is my sensitive data safe?
Yes. JSON/YAML/CSV you paste is NOT uploaded to any server. All processing happens locally in your browser.
Is there a size limit?
Browser RAM dependent. Files under 10MB run smoothly. Larger files may freeze the tab.
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