Apereo CAS vs Clerk
Apereo CAS
apereo.orgClerk
clerk.comSide by side
| Figure | Apereo CAS | Clerk |
|---|---|---|
| Price from | Free | $1.67/mo |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| iOS | — | Yes |
| Android | — | Yes |
| API | Yes | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 4 |
| Spec score · Authentication Software | 8.2 (#11) | 8.5 (#5) |
| Integrations | CAS provides integrations with SAML2 service providers and supports SCIM, reCAPTCHA, and Swagger. | Clerk documents integrations with Convex, Firebase, Supabase, Shopify, Vercel Marketplace, and Google Analytics. |
| Support | Apereo staff do not provide technical project support but direct users to project communities and mailing lists, including CAS security, developer, and user lists. | Business includes priority support, while Enterprise includes a premium support SLA and dedicated Slack channel. |
Plans
In their own words
Clerk
Clerk provides full-stack authentication and user management for applications, including Organizations and Billing. Prebuilt components cover sign-up, sign-in, and user profiles, while Frontend, Backend, and Platform HTTP APIs support client-side, backend, and workspace operations. Clerk Billing handles subscription billing and charges 0.7% of billing volume in addition to Stripe fees. Its free B2B offering includes 100 monthly retained organizations per app and up to 20 members per Organization. Listed integrations include Convex, Firebase, Supabase, Shopify, Vercel Marketplace, and Google Analytics. Security practices include account lockout, bot protection, rate limiting, breached-password detection, and MFA enforcement. Clerk lists SOC 2 Type 2 and HIPAA certifications; SOC 2 reports are available on Business and above, while a HIPAA BAA is available on Enterprise. Data is hosted on US infrastructure, with no regional data residency. Clerk is available on Android, iOS, web, APIs, and extensions, and provides an iOS SDK for native Apple apps. Hobby is free; Pro costs $20/mo billed annually, and Business costs $250 per year billed annually.