HS256 vs RS256 — Which JWT Algorithm to Use?
Compare HS256 and RS256 JWT signing algorithms. Learn when to use symmetric vs asymmetric keys for JWT security.
Quick Answer
HS256 vs RS256 — Which JWT Algorithm to Use? is a JWT signing algorithm. Use our Decoder to check which algorithm a token uses, then verify with the matching key in our Validator or JWKS Validator.
HS256 — Symmetric
Uses one shared secret. Simple but every service that verifies tokens must know the secret.
| Pros | Cons |
|---|---|
| Fast, simple setup | Secret must be shared with all verifiers |
| Good for monoliths | Secret leak compromises all tokens |
RS256 — Asymmetric
Private key signs, public key verifies. Ideal for microservices and OAuth/OIDC.
| Pros | Cons |
|---|---|
| Public key can be distributed via JWKS | Slower, more complex key management |
| Private key never leaves auth server | Requires certificate/key rotation plan |
Recommendation
- Monolith / internal APIs → HS256 with strong secret (256+ bits)
- Public APIs / OAuth / microservices → RS256 or ES256
Using HS256 vs RS256 — Which JWT Algorithm to Use? Safely
Algorithm HS256 vs RS256 — Which JWT Algorithm to Use? defines JWT signing. Validate the header alg matches expectations. Use JWKS for asymmetric keys; protect HMAC secrets.
Browse related resources: JWT Decoder, JWT Validator, JWT Basics, JWT Authentication, JWT Errors, Algorithms, Glossary, and Learning Path.
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FAQ
What is HS256?
HMAC-SHA256 — symmetric algorithm using a shared secret for signing and verification.
What is RS256?
RSA-SHA256 — asymmetric algorithm using a private key to sign and public key to verify.
Which is more secure?
RS256 is better for distributed systems since only the auth server holds the private key.