Developer Tools
Decode and view only the JWT header section without focusing on the payload.
Use this JWT Header Viewer to decode only the first part of a JWT token and display the header as readable JSON. It is useful when you only need to inspect header values such as alg, typ, kid, cty, and other metadata without parsing the full payload.
Use this JWT Header Viewer to decode only the first part of a JWT token and display the header as readable JSON. It is useful when you only need to inspect header values such as alg, typ, kid, cty, and other metadata without parsing the full payload.
Use jwt header viewer when you need a fast browser-based result without extra setup. It works well for quick checks, one-off tasks, and routine formatting or calculation work.
Read step-by-step usage guidance, best practices, and common mistakes.
See common questions and answers about input, output, and tool usage.
Review practical input and output examples before running the tool.
Find similar and supporting tools for adjacent actions and follow-up tasks.
Input
eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjMifQ.signature
Output
{
"alg": "HS256",
"typ": "JWT"
} Useful when checking only the algorithm and token type.
Input
eyJhbGciOiJSUzI1NiIsImtpZCI6ImtleS0xIiwidHlwIjoiSldUIn0.eyJzdWIiOiIxMjMifQ.signature
Output
{
"alg": "RS256",
"kid": "key-1",
"typ": "JWT"
} Helpful when troubleshooting key selection and signing metadata.
Fix: Paste the full JWT token with header, payload, and signature sections.
Fix: Use JWT Decoder or JWT Parser if you need the payload.
Fix: Check whether the token was copied fully and is actually a JWT.
It decodes and shows only the header part of a JWT token.
Common fields include alg, typ, kid, and sometimes cty.
No. It only decodes the header.
JWT Header Viewer focuses only on the first JWT segment, while JWT Decoder shows the broader token content.
Use it when you only need header metadata and do not want payload details.