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JWT Signature Verifier

Verify JWT signatures with HS256, RS256, and ES256.

Output will appear here…

How to Use This Tool

  1. Fill in JWT Token, Secret (HS), and Public Key (RS/ES). Each control is labeled; you do not need to paste a JSON blob.
  2. Click "Run" to run the tool in your browser.
  3. Read the result below the form and copy it if you need it in another app.

Learn More About JWT Signature Verifier

About JWT Signature Verifier

Verify JWT signatures using HS256, RS256, or ES256. All crypto runs in the browser.

About

Verify JWT signatures using HS256, RS256, or ES256. All crypto runs in the browser.
Verify JWT signatures using HS256, RS256, or ES256. All crypto runs in the browser.
Runs in browser
Yes
No signup required
Yes

Examples

HS256 John Doe payload

HS256 John Doe payload
Input
{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMiLCJuYW1lIjoiSm9obiBEb2UifQ.0R1o1FvNWw2JDr6-DjgrBg645S00OP9f6GaqVUZD9sA",
  "secret": "azweb-tools-example-secret",
  "publicKey": ""
}
Output
✓ JWT signature verified!
Algorithm: HS256

── Payload ──
{
  "sub": "123",
  "name": "John Doe"
}

HS256 admin role payload

HS256 admin role payload
Input
{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ1c2VyLTQyIiwicm9sZSI6ImFkbWluIn0.y2N_-AEV-BL3TdgxJ9vBiX962RvN_Ruu-kBURqKbL5s",
  "secret": "azweb-tools-example-secret",
  "publicKey": ""
}
Output
✓ JWT signature verified!
Algorithm: HS256

── Payload ──
{
  "sub": "user-42",
  "role": "admin"
}

HS256 email claim payload

HS256 email claim payload
Input
{
  "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhY2N0LTkiLCJlbWFpbCI6ImFnZW50QHRzdC5pbnZydW4udG9wIn0.MS-rV9IiSCsUj9PQIoSvT5oRN-Cm-as7c_SRNFRTO0I",
  "secret": "azweb-tools-example-secret",
  "publicKey": ""
}
Output
✓ JWT signature verified!
Algorithm: HS256

── Payload ──
{
  "sub": "acct-9",
  "email": "agent@tst.invrun.top"
}

Use Cases

  • Check jwt signature verifier values while you draft a page, spreadsheet, or config.
  • Fill JWT Token, Secret (HS), Public Key (RS/ES) and compare the result to a second source.
  • Keep sensitive inputs on-device — this page runs the calculation in the browser.

Frequently Asked Questions

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