Use OIDC for new apps, especially web, mobile and API driven ones. Support SAML when enterprise customers or older internal tools need it. Both deliver a signed statement about who signed in. They differ in format, flow and the mistakes they invite.
What each one is
SAML uses signed XML assertions, passed through the browser between an identity provider and a service provider. It is common in workplace single sign-on for older and enterprise software.
OIDC is an identity layer on OAuth 2.0 and uses signed JSON Web Tokens. The ID token carries required claims such as iss, sub, aud, exp and iat. The same protocol family also gives you access tokens for APIs.
Side by side
| SAML | OIDC | |
|---|---|---|
| Token format | Signed XML assertion | Signed JWT (ID token) |
| API access | Not designed for it | Built on OAuth 2.0, so yes |
| Mobile and single page apps | Awkward | Natural fit |
| Typical user | Enterprise workforce SSO | Consumer and workforce, modern apps |
| Main parsing risk | XML signature handling | JWT validation mistakes |
When SAML is the right answer
- A customer's identity team says SAML is what their provider and procurement expect.
- You integrate with software that only offers SAML.
- You already operate a SAML federation and the cost of change is not justified.
When OIDC is the right answer
- New application, or one with mobile, desktop or API clients.
- You want one protocol for both sign in and API authorization.
- Your team is more comfortable validating JWTs than XML signatures.
What each leaves on you
For SAML, the hard part is validation: signature wrapping, Destination, Audience, time windows and replay. The OWASP cheat sheet is a good checklist, and our SAML validation checklist summarizes it.
For OIDC, the hard part is checking the ID token every time and using the right flow. See the ID token validation checklist and use authorization code with PKCE.
Supporting both
Many B2B products end up offering both: OIDC as the default and SAML for enterprise buyers. If you do, normalize both into one internal user model keyed by issuer and subject, so downstream code does not care which path was used. Pair this with automated provisioning, covered in what SCIM does.
A decision rule
If you must pick one tomorrow with no other constraints, pick OIDC. If a signed customer deal requires SAML, add it. Do not build SAML from scratch. Use a maintained library and keep it patched.
Quick check
Is SAML insecure and OIDC secure?
No. Both are sound when implemented carefully, and both have had serious implementation bugs. Pick on fit, then validate strictly.
Can OIDC replace SAML for enterprise customers?
Often yes, but some customers still require SAML. Check what their identity provider and policies expect.
Sources
Last reviewed: 19 October 2026.
