JWTデコーダー

使い方

JSON Webトークン(JWT)をデコードして検査します。ヘッダー、ペイロード、クレーム、有効期限を確認できます。

1. 1Paste a JWT token (three Base64url segments separated by dots) into the input field.
2. 2The tool decodes and displays the Header, Payload, and Signature sections.
3. 3Review the claims in the Payload: `iss`, `sub`, `exp`, `iat`, and any custom claims.
4. 4Check the expiration status — the tool highlights whether the token is expired.

主な機能

• Decodes JWT header, payload, and signature without any server request
• Displays all standard and custom claims in formatted JSON
• Shows token expiration status and remaining time or time since expiry
• Handles HS256, HS384, HS512, RS256, and other common algorithms

よくある質問

詳しく読む

• API Security Best Practices for Developers