JWT sign (RSA / ECDSA)
ClientSign with a PEM private key locally via Web Crypto.
About JWT sign (RSA / ECDSA)
Sign RS256/384/512 or ES256/384/512 JWTs with a PKCS#8 PEM private key in the browser—Web Crypto only. The interactive transform on this page runs in your browser tab—Toolcore does not need your paste for the core operation described above.
How to use this page
Paste or type in the main workspace, run the primary action from the toolbar, then copy or download the result. Use Load example when the page offers it, or URL prefill (?q= / ?qb=) so agents and tickets open the same input.
Limits and safety
Utilities here are for development and inspection—do not paste live production keys, PANs, or recovery codes into any browser tab you do not control.
Nearby workflows on Toolcore
- JWT verify (RSA / ECDSA) — Verify RS256/384/512 or ES256/384/512 JWTs with a PEM public key in the browser—Web Crypto only. before you trust a token, digest, or key material in production.
- JWT sign & verify — Sign HS256/384/512 JWTs or verify HMAC signatures in the browser—pair with JWT decode for claims. before you trust a token, digest, or key material in production.
- JWT decode — Inspect JWT header and payload as JSON in browser; signature not verified. before you trust a token, digest, or key material in production.
- PEM / X.509 viewer — Decode PEM certificates in the browser—subject, issuer, validity; paste only what you trust. before you trust a token, digest, or key material in production.
Common use cases
- JWT sign (RSA / ECDSA) for quick local checks without uploading data.
- Copy results into tickets, docs, or classroom notes.
Common mistakes to avoid
Unexpected input shape
See the intro and how-to notes for accepted formats.
FAQ
Is processing local?
Yes—this runs entirely in your browser.
Agent prefill?
Use q or qb for the main text field when supported.
Common search terms
Phrases people search for that match this tool. See the full long-tail keyword index.
- jwt sign rsa online pem
- jwt rs256 sign private key browser
- ecdsa jwt sign pem local
More tools
Related utilities you can open in another tab—mostly client-side.
JWT verify (RSA / ECDSA)
ClientVerify RS256/384/512 or ES256/384/512 JWTs with a PEM public key in the browser—Web Crypto only.
JWT sign & verify
ClientSign HS256/384/512 JWTs or verify HMAC signatures in the browser—pair with JWT decode for claims.
JWT decode
ClientInspect JWT header and payload as JSON in browser; signature not verified.
PEM / X.509 viewer
ClientDecode PEM certificates in the browser—subject, issuer, validity; paste only what you trust.