Generate an RS256 JWT locally

Use a PKCS#8 PRIVATE KEY PEM. The header algorithm is forced to RS256 so the tool cannot silently sign one algorithm while labeling another.

Header JSON

{"typ":"JWT"}

Payload JSON

{"sub":"123","name":"Alex","exp":4102444800}

PKCS#8 private key PEM

Generated token

Matching public key (shown for generated demo keys)

Private-key operations run in this browser. Protect production signing keys according to your real application's key-management policy; an online utility is not an HSM or production signing service.

Local developer workflow

This v10.72 layer keeps high-frequency developer jobs browser-local and connects focused tools without replacing their established engines. JSON, Base64, URL, UUID and JWT content is processed in the browser; YAML may use the existing optional parser library when available, with its documented local fallback.

Trust and standards boundaries

Formatting is not schema validation, Base64 is not encryption, URL normalization is not a privacy guarantee, UUID metadata is not provenance, and decoded JWT claims are not trusted until cryptographic and application-specific validation succeeds. RS256 tools accept explicit PEM key formats and do not fetch issuer keys or make authorization decisions.

How to use this JWT RS256 Generator

Generate RS256 JWTs locally from JSON header/payload and a PKCS#8 PRIVATE KEY PEM, with an optional ephemeral demo key pair.

Enter, paste, upload, or choose the inputs shown in the tool above.
Adjust the available options for the result you need.
Review the output before copying, downloading, or using it elsewhere.

What this tool does

Sign test JWTs in your browser without uploading the private key and keep production key-handling responsibility explicit.

Practical tips and limits

Review the inputs and result before using the output elsewhere. Keep the original data when the operation changes or replaces content.