Inspect a bearer token payload
入力
eyJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4ifQ.signature
出力
Header: {"alg":"HS256"}
Payload: {"sub":"1234567890","name":"John"}
JWT パーサー とは何ですか？
JWT Decoder is useful when authentication breaks and you need to answer practical questions fast: who issued the token, when it expires, what audience it targets, and whether the payload looks sane.
JWT パーサー の使い方
- Paste the JWT into the decoder.
- Read the header and payload claims in a human-friendly format.
- Use the decoded timestamps and claim values to debug auth or API issues.
例
よくある質問
Does this page verify a JWT signature?
It focuses on decoding and inspection. Signature verification still depends on validating the token with the correct secret or public key in your own auth flow.
Can I inspect an expired token?
Yes. Expired tokens can still be decoded, which is often exactly what you need during debugging.
Is the token uploaded to a server?
No. The decoding happens in the browser.