JWT Decoder

Decode JWT header and payload in your browser. Inspect claims instantly — decode only, no upload, free online JWT decoder.

Decode a JWT privately in your browser

Paste a JWT to inspect its header and payload claims. Decoding is local only — useful for debugging auth tokens without sharing them.

What you can do with it

Debug an auth token
Check expiry (exp), subject (sub), and custom claims without calling a remote debugger.
Confirm algorithm and type
Read the header to see alg and typ before wiring verification elsewhere.

How to decode a JWT

  1. Paste the JWT into the input.
  2. Click Decode to view header and payload as JSON.
  3. Copy the parts you need — signature is shown but not verified.

Inspect JWT claims without sending the token away

Auth tokens in bug reports are sensitive. Decoding header and payload locally lets you check exp, sub, and roles without pasting into a hosted JWT debugger. Signature verification is intentionally out of scope — use your auth library for that.

Decode-only by design

Seeing claims does not prove the token is valid. Always verify signatures server-side. This tool is for inspection and debugging only.

Related reading and tools

Frequently asked questions

Is my token uploaded?
No. Decoding runs entirely in your browser. The token never leaves your device.
Does this verify the signature?
No. This tool only decodes the header and payload. It does not validate signatures or trust the token.
What token formats are supported?
Standard JWTs with three Base64URL parts (header.payload.signature).

Related tools

View all Developer Tools