About
JWT

JWT Decoder

Inspect JWT headers and payloads

Usage guide and feature details

What is a JWT decoder for?

It helps inspect claims and expiration during debugging. Decoding does not validate the signature, so servers must still verify every token.

JWT Decoder is a free online utility for development, testing, and everyday data tasks. It is designed to Inspect JWT headers and payloads. No software installation or account is required.

Practical example and boundaries

Inspect public token claims

JWT Decoder separates the header, payload and signature and decodes Base64URL content so you can inspect algorithms, issuer, audience and expiry claims.

Example input

Header: {"alg":"HS256","typ":"JWT"}
Payload: {"sub":"123","exp":1893456000}

Expected output

alg = HS256
sub = 123
exp = 2030-01-01 00:00:00 UTC

Limitations and cautions

Decoding is not verification. Without a key, this tool cannot confirm the signature, issuer, audience or trustworthiness of a token.

Key features of JWT Decoder

  • Process input instantly and spend less time switching between editors, terminals, and third-party apps.
  • Calculations run in your current browser by default, making the tool suitable for code, configuration, and debugging data.
  • Use essential features without registration, sign-in, or routine usage limits.
  • Works on desktop and mobile browsers with clear results that are easy to edit, copy, or download.

How to use JWT Decoder

  1. Enter, paste, or select the content in the tool above, then adjust any available options.
  2. Choose the relevant action and JWT Decoder will process and validate the input directly in your browser.
  3. Review the output, make any required changes, then copy the result or download the available file.

Common uses for JWT Decoder

Use JWT Decoder while building front-end pages, debugging APIs, reviewing configuration, preparing test data, or working on technical documentation. It helps you Inspect JWT headers and payloads, which is useful for quick checks, one-off conversions, and repetitive development tasks.

Frequently asked questions about JWT Decoder

Can this page tell whether a JWT is valid?

No. A server must verify the signature with an allowed algorithm and check exp, nbf, iss and aud claims.

Is JWT Decoder free to use?

Yes. JWT Decoder is free to use without registration and is designed to Inspect JWT headers and payloads.

Is my input uploaded when I use JWT Decoder?

This tool runs locally in your browser. Your input is never sent to our servers.