JWT Encode Online — HS256 Only

Sign a compact JWT with HS256 from JSON claims and a secret. Convenience expiry presets. Does not verify signatures — pair with JWT Decode to inspect the result.

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JWT encode — HS256 signing helper
Sign compact JWTs with HS256 from JSON claims and a secret. Convenience exp presets. Does not verify.

How JWT encode works

Paste a JSON claims object and a secret. Header is locked to alg=HS256, typ=JWT. iat is always set to now. If an expiry preset is selected, exp is overwritten. Encoding is not verification — use jwt-decode to inspect, and your identity stack for trust.

Options

Expiration preset
none leaves exp alone; 15m / 1h / 24h set exp = iat + offset (overwrites prior exp).

Examples

Basic claims

Claims

{ "sub": "1234567890", "name": "Jane Doe", "role": "qa", "scope": "orders:read orders:write inventory:read", "iss": "fastminify-local-fixture", "aud": "fastminify-devtools", "note": "Local HS256 fixture claims only — not production auth" }

Result

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.… (HS256 compact JWT)

Inspect after encode

Claims

Encode then paste into jwt-decode

Result

Header shows HS256; payload shows iat/exp claims

Related tools

Inspect tokens with jwt-decode. Review JWKS locally via inspect-jwks. Encoding here does not replace a verified auth flow.

JWT encode FAQ

HS256 only

Does this verify JWTs?

No. It only signs HS256 tokens. Use your auth server or JWKS verifier for trust. See jwt-decode to inspect.

Which algorithms are supported?

HS256 only in v1. RS256/ES* and alg=none are out of scope.

Is this a secure JWT for production?

This is a local helper for fixtures and debugging — not a claim that tokens are “secure” or production-ready auth.

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