PTPureToolkit
SecurityLocal-only

JWT Decoder

Decode JSON Web Token header and payload locally in your browser. This tool does not verify signatures.

This tool runs locally in your browser. Your input is not uploaded.

No uploadsNo server logsNo runtime APIsBrowser-only transforms

Decoded JWT

Run the tool to generate local output.
Options

Examples

Sample token

A signed-looking sample token for local inspection.

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJkZXZlbG9wZXIiLCJuYW1lIjoiTG9jYWwgVG9vbHMiLCJpYXQiOjE3MzY5NDAwMDB9.invalid-signature

Unsigned-style demo

A token-shaped value that demonstrates decoded JSON claims.

eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJyb2xlIjoiZGVtbyIsImxvY2FsIjp0cnVlfQ.signature

How it works

  1. The token is split into header, payload, and signature segments.
  2. Header and payload are decoded from Base64URL and parsed as JSON.
  3. The signature is displayed but not verified.

Limitations

  • Signature verification is not supported in this browser-only scaffold.
  • Decoded claims are informational and should not be treated as trusted proof.

FAQ

Does this JWT decoder verify signatures?

No. It only decodes the token segments for inspection and clearly warns that signatures are not verified.

Can I paste production tokens?

The tool runs locally, but sensitive credentials should still be handled according to your organization policy.

Related tools

JSON Formatter and ValidatorFormat, minify, and validate JSON locally with deterministic native parsing.Base64 Encoder and DecoderEncode and decode Unicode text as Base64 entirely in the browser.URL Encoder and DecoderEncode or decode URL components and full URL strings without network requests.