WorkOS is the pick when a deal is waiting on SAML, SCIM and audit logs, because it treats enterprise sign-on as a separate concern from your existing login. It is managed cloud only, with no self-hosting. If you have not sold an enterprise deal yet, several cheaper options below will carry you until you do.
8 tools reviewedLast reviewed Ranked by us, not by votes
What counts as auth providers for SaaS
Auth providers for SaaS are hosted or self-hosted services that own sign-in, session handling, single sign-on and user management on behalf of an application, so the team does not build and maintain that layer itself. A product belongs here if it delivers login flows, session or token issuance, and a user store as its primary function, whether as a managed API, an open source server you run, or a library you embed. Adjacent categories such as standalone fraud scoring, API gateways and full backend platforms are excluded unless authentication is the core offering. Starter templates and boilerplate that merely ship auth code inside an application do not qualify, because the buyer still owns and operates the resulting system.
How we judged them
Entries were judged on the three things buyers get wrong most often: how well enterprise single sign-on is supported (SAML and OIDC connections, SCIM directory sync, and whether customer IT can self-serve setup), where the pricing model creates a cliff as user counts or enterprise customer counts grow, and how expensive it would be to leave, which mostly comes down to whether password hashes can be exported and how much application logic is locked into vendor-specific extension points. Open source availability and self-hosting were treated as a hedge against both pricing and exit risk rather than as a virtue on their own. Every claim was checked against the vendor's own site or repository during this research. Pricing is described by shape only, since published rates change.
All 8 auth providers for SaaS in this guide, in ranked order.
workos.com · Free tier for user management up to a high monthly-active-user threshold, then usage-based; enterprise SSO and directory sync billed per connection per month with volume discounts, plus an optional prepaid annual credits plan.
Best for B2B SaaS teams whose next deals require SAML, SCIM and audit logs, and who want enterprise sign-on decoupled from per-user billing.
WorkOS sells enterprise authentication building blocks, including a hosted sign-in product (AuthKit), SAML and OIDC single sign-on, SCIM directory sync, and audit logs.
Strengths
Enterprise single sign-on is the core product rather than an upsell: one integration covers SAML and OIDC across a broad set of identity providers.
Directory sync and SCIM provisioning are first-class, which is usually the second thing an enterprise buyer asks for after SSO.
An admin portal lets the customer's own IT team configure their connection without your engineers joining a call.
User management is free up to a very high monthly-active-user threshold, so consumer-scale growth does not by itself trigger a bill.
Where it falls short
No self-hosting: WorkOS is a managed cloud service only.
Enterprise SSO and Directory Sync are billed per connection per month, so cost scales with the number of enterprise customers rather than with revenue from them.
The largest connection volumes and custom enterprise agreements are not publicly priced and require contacting sales.
The product is oriented toward B2B; teams with only consumer sign-in get less value from the parts they pay for.
clerk.com · Tiered plans (free through enterprise) priced on monthly retained users, with separate per-connection charges for enterprise SSO and paid add-ons for B2B organizations and machine authentication.
Best for Product teams on modern JavaScript frameworks who want working sign-in, sessions and account UI in a day rather than a sprint.
Clerk is a hosted authentication and user management service with prebuilt UI components and SDKs for React, Next.js, Expo, Astro and similar frameworks.
Strengths
Drop-in UI components and framework-specific SDKs remove most of the front-end work for sign-in, sign-up and account management.
Billing counts monthly retained users rather than every signup, so one-time and abandoned signups do not inflate the bill.
The free tier is large enough that many products reach real traction before paying anything.
B2B organizations, custom roles, invitations and user impersonation are available without building a tenancy model from scratch.
Where it falls short
No self-hosting: user records and sessions live in Clerk's infrastructure.
SAML and other enterprise connections are billed per connection, on top of the plan.
B2B organizations with unlimited members and custom roles is a paid add-on rather than part of the base plan, and MFA, custom email templates and expanded impersonation sit behind higher tiers or add-ons.
Exceeding the free tier forces an upgrade after a grace period rather than degrading gracefully.
Deep use of Clerk components and hosted session handling means a migration touches both the user store and the front end.
Best for TypeScript teams who want to own their user data and avoid per-user pricing, and who are comfortable operating auth themselves.
Better Auth is an open source TypeScript authentication framework that runs inside your own application and stores users in your own database, with plugins for SSO, organizations, passkeys and MFA.
Strengths
MIT licensed and self-hosted by design: users, sessions and credentials stay in your database, which makes exit cost close to zero compared with hosted services.
No per-monthly-active-user charge for the library itself, so growth does not create a pricing cliff.
Plugin coverage extends past basic login into SAML 2.0, SCIM and directory sync, organizations with teams and roles, passkeys, two-factor, API keys and JWTs.
Configuration lives in code, so auth changes go through the same review and version control as the rest of the application.
Works across a wide range of frameworks (Next.js, Nuxt, SvelteKit, Astro, Hono and others) rather than a single one.
Where it falls short
TypeScript and JavaScript only: it is not an option for backends written in other languages.
You operate it. There is no managed SLA for the library itself, and availability, upgrades and security patching are your responsibility.
The project was acquired by Vercel in July 2026, so governance and roadmap direction now sit with a commercial owner even though the license remains MIT.
It is a younger project than the incumbents, with a correspondingly shorter track record on large enterprise deployments.
Hosted dashboard features such as user management and audit logs are a separate commercial offering rather than part of the library.
stytch.com · Self-serve pay-as-you-go priced on monthly active users with a free allotment of users and SSO/SCIM connections, per-connection charges beyond that, optional add-ons, and a quote-only enterprise tier.
Best for B2B SaaS teams that want tenant-aware auth, self-serve enterprise SSO setup and bot or fraud defense from a single vendor.
Stytch provides authentication and authorization APIs for both B2B and consumer applications, with built-in multi-tenancy, device fingerprinting and fraud prevention.
Strengths
Multi-tenancy is built in: organizations, per-organization auth policies and an embeddable admin portal let customers configure their own SSO and SCIM.
Enterprise SSO covers both SAML and OIDC and works with role-based access control out of the box.
Device fingerprinting, bot detection and rate limiting are part of the platform rather than a separate vendor.
Pay-as-you-go pricing is published rather than quote-only, and includes a number of free SSO and SCIM connections before charges start.
Where it falls short
No self-hosting: it is a hosted API service.
SSO and SCIM connections are billed per connection once the included allotment is used, so cost tracks enterprise customer count.
The Enterprise tier is quote-only, so the highest-volume and unlimited-connection terms are not publicly priced.
Some capabilities, including fraud prevention and brand customization, are priced as separate add-ons.
Smaller community and third-party ecosystem than Auth0 or Clerk, which means fewer worked examples for unusual stacks.
auth0.com · Free tier with a monthly-active-user cap, then tiered plans (Essentials, Professional, Enterprise) priced on monthly active users, with separate B2C and B2B price structures and quote-only enterprise terms.
Best for Teams with complex or unusual identity requirements, or those that need a vendor with a long compliance and enterprise track record.
Auth0, owned by Okta, is a mature identity platform covering consumer and B2B authentication, enterprise SSO, MFA, machine-to-machine tokens and fine-grained authorization.
Strengths
The broadest protocol and feature coverage among the hosted options: social and passwordless login, adaptive MFA, SAML, SCIM, machine-to-machine authorization and fine-grained authorization in one platform.
Actions and Organizations provide extension points and multi-tenancy without custom infrastructure.
Long operating history with extensive documentation, SDK coverage and third-party integrations.
Enterprise plans offer private deployment, a high uptime SLA and compliance options including a HIPAA BAA.
Where it falls short
B2B and B2C are priced as separate structures, and the B2B track is materially more expensive at comparable user counts.
Pricing is monthly-active-user based with tier steps, which is the classic source of a cost cliff as usage grows.
Capabilities many teams treat as baseline (private deployment, enterprise SLA, Credential Guard, bot detection, HIPAA BAA, custom SSO tiers) are gated to the quote-only Enterprise plan.
No self-hosting on standard plans; private deployment is an enterprise-only arrangement.
Logic written into Actions and heavily customized Universal Login is vendor-specific and has to be rebuilt if you leave.
keycloak.org · Free and open source under Apache 2.0; costs are infrastructure and staff time, with optional paid support available from third-party vendors.
Best for Teams with operations capacity that need full enterprise SSO and directory federation with no per-user licensing and no vendor dependency.
Keycloak is an open source identity and access management server and a CNCF incubating project, supporting OpenID Connect, OAuth 2.0, SAML 2.0, identity brokering and LDAP or Active Directory federation.
Strengths
Apache 2.0 licensed with no per-user or per-connection cost, which removes pricing cliffs entirely.
Full SAML 2.0, OIDC and OAuth 2.0 support plus identity brokering, so it interoperates with essentially any enterprise identity provider.
User federation against LDAP and Active Directory is built in, which matters for on-premises and hybrid enterprise customers.
CNCF incubating status, container images and a Kubernetes operator give it a credible governance and operations story.
Data stays in your own database, so leaving is a data migration rather than a rebuild.
Where it falls short
No official hosted service from the project: you run, scale, patch and back it up yourself, including clustering and database operations.
Commercial support requires going to a third-party vendor rather than to the project.
Administration and theming are heavier and less polished than the hosted developer-focused options, and custom login UI work is non-trivial.
Major version upgrades have historically introduced breaking changes that require planned migration work.
supabase.com · Free, Pro, Team and Enterprise plans with authentication billed on monthly active users above an included allotment, and SAML single sign-on limited to paid plans; self-hosting is free.
Best for Teams already building on Supabase or Postgres who want authentication and database-level authorization to be the same system.
Supabase Auth is an MIT-licensed Go authentication server that issues JWTs and stores users in a Postgres schema, offered both as part of hosted Supabase and as a self-hostable component.
Strengths
Authorization policies are enforced in Postgres via row level security using the authenticated user's JWT claims, which removes a layer of middleware.
MIT licensed and self-hostable via Docker or the CLI, so the hosted service is not the only way to run it.
Covers a wide range of sign-in methods out of the box: more than twenty social providers, email and password, phone OTP, magic links, TOTP MFA and SAML 2.0.
User records live in your own Postgres instance, which makes both inspection and migration straightforward.
Where it falls short
Requires Postgres: user data lives in an auth schema in a Postgres database, so it is not a drop-in for teams on another datastore.
SAML 2.0 single sign-on is restricted to paid plans, with enterprise terms requiring contacting sales.
Authentication is billed on monthly active users above the plan allotment, so consumer scale does create overage cost on hosted Supabase.
On the free hosted plan, projects are paused after a period of inactivity and the number of concurrent projects is capped.
B2B multi-tenancy features such as organizations, roles and invitations are less developed than in the B2B-focused vendors, so more of that layer is yours to build.
aws.amazon.com · Usage-based on monthly active users across three feature plans (Lite, Essentials, Plus), with federated SAML and OIDC users billed at a separate lower rate, and a permanent free tier for both categories.
Best for Teams already standardized on AWS that want authentication inside the same account, billing relationship and IAM model as the rest of their infrastructure.
Amazon Cognito is AWS's managed identity service, providing user pools for sign-in and user directories, identity pools for AWS credential exchange, and federation with SAML and OIDC providers.
Strengths
Integrates natively with AWS IAM, API Gateway and other AWS services, including short-lived credential exchange through identity pools.
Per-user cost at high volume is typically well below the developer-focused hosted vendors, and federated SAML or OIDC users are billed at a lower rate than direct sign-ins.
A permanent free tier applies to both direct sign-ins and a smaller allotment of federated users, and it does not expire.
Supports passwordless sign-in with WebAuthn passkeys and OTP, plus risk-based adaptive authentication and compromised credential monitoring on the highest feature plan.
Where it falls short
Password hashes cannot be exported from a user pool, so leaving Cognito requires either forcing password resets or running a migration Lambda trigger that moves users gradually as they sign in. This is the highest exit cost in this list.
Security features are split across the Lite, Essentials and Plus feature plans, so threat detection and adaptive authentication require the most expensive plan.
User pools are regional resources with no built-in cross-region replication of a pool.
Hosted sign-in UI customization is more constrained than the component libraries offered by Clerk or Stytch.
Developer experience, SDK ergonomics and documentation are commonly cited as weaker than those of the specialist vendors.