QCSunny Lab

JWT Decoder & FormatterJWT 令牌解码与格式化

Inspect and format JSON Web Tokens (JWT) instantly in your browser. Splits the token into Header, Payload, and Signature, and decodes Base64URL data with UTF-8 character support.

Automatically parses expiration (exp), issued-at (iat), and not-before (nbf) timestamps into human-readable local time, displaying live validity countdowns and status indicators.

Frequently asked questions

Is it safe to paste production tokens?

Yes. Unlike typical online JWT decoders that may log your Bearer tokens, this tool runs 100% locally with zero network requests.

Can this tool verify or create signatures?

Yes — for the HMAC family. Enter a secret above and use "Verify Signature (HMAC)" to check HS256/384/512 tokens, or "Sign Payload → JWT" to mint one from a payload JSON. RS/ES (asymmetric) algorithms need a public key and are not supported.

中文说明

在浏览器中极速解析 JSON Web Token (JWT) 令牌。自动将 Token 拆分为 Header 头部、Payload 载荷数据与 Signature 签名串,并完整支持 UTF-8 中文字符解码。

自动识别 exp(过期时间)、iat(签发时间)与 nbf(生效时间)时间戳,转换为本地时区的人类可读时间,并直观提示当前 Token 是有效还是已过期。

常见问题

在这里粘贴生产 Token 安全吗?

绝对安全。绝大多数在线 JWT 网站存在泄露甚至截获 Token 的风险,而本工具 100% 纯前端解码,无任何后台网络请求。

本工具可以验签或签发 Token 吗?

可以(HMAC 系列)。在上方输入密钥后,"验签 (HMAC)" 可校验 HS256/384/512 Token,"签发 Payload → JWT" 可由 Payload JSON 生成完整 Token。RS/ES 非对称算法需要公钥,暂不支持。