The 5 best Firebase Auth alternatives in 2026

Firebase Authentication has been the default starting point for app developers for over a decade. The free tier is generous, the SDKs drop in cleanly, the integration with Google Cloud is deep, and the time to first login is hard to beat. For consumer apps, mobile-first products, and early-stage companies, that combination has been good enough to make Firebase Auth the obvious first choice.

But teams scaling past the early stage tend to hit the same set of walls. Enterprise prospects ask for SAML SSO, SCIM provisioning, and audit logs that Firebase Auth does not ship natively, which pushes teams to upgrade to Google Cloud Identity Platform (GCIP). GCIP unlocks some of those features but introduces per-tenant billing and still leaves you to build the admin portal your customers' IT teams expect. Google Cloud lock-in becomes a strategic concern as teams consolidate on other clouds or weigh vendor independence. And Firestore's NoSQL constraints around joins, aggregations, and complex queries often kick off a broader re-evaluation of the whole Firebase stack, with auth migrating along with the database.

If any of those pressures resonate, there are stronger alternatives worth a serious look. In this article, we compare five of the top Firebase Auth alternatives for B2B SaaS in 2026, including what each does well and where it falls short.

Why should you consider a Firebase Auth alternative?

Here are three reasons teams are re-evaluating Firebase Auth in 2026.

B2B and enterprise feature gaps

Firebase Auth was built around consumer authentication patterns: email/password, phone OTP, social logins, anonymous users. The B2B and enterprise surface area is thin. There is no native SAML SSO, no SCIM provisioning, no organization-based multi-tenancy, and no out-of-the-box audit log pipeline that compliance teams will accept.

The official path forward is Google Cloud Identity Platform (GCIP), which adds SAML support and tenant isolation but introduces per-tenant billing and still does not ship SCIM or a hosted admin portal for your customers' IT teams. By the time you have stitched together GCIP plus a custom admin UI plus a homegrown audit log export, you have built a worse version of what purpose-built B2B platforms ship out of the box, and you own the ongoing maintenance.

Google Cloud lock-in and vendor independence

Firebase Auth is tightly coupled to Google Cloud. User records, session management, admin tooling, and the underlying identity infrastructure all live inside GCP. Migration off Firebase is real engineering work, especially around password hash export and session continuity for active users.

For teams consolidating on AWS or Azure, building toward multi-cloud, or weighing vendor independence as a strategic factor in their procurement story, that coupling becomes harder to justify over time. The closer your auth stack sits to a single cloud provider's roadmap and pricing, the less leverage you have when either changes.

Relational data needs and the Firestore problem

Most Firebase apps use Auth and Firestore together. The two products are technically independent, but in practice they ship as a bundle, and the developer experience leans on the integration. As products grow, Firestore's NoSQL constraints around joins, aggregations, and reporting queries push teams to evaluate Postgres-based alternatives like Supabase or Neon.

Once a database migration is on the table, auth tends to come with it. That is why "Firebase alternatives" conversations almost always end up being "Firebase and Firestore alternatives" conversations, and why open-source Postgres-first platforms have become the default landing spot for teams leaving Firebase entirely.

Top Firebase Auth alternatives in 2026

1. WorkOS
2. Auth0
3. Supabase Auth
4. FusionAuth
5. AWS Cognito

1. WorkOS

WorkOS is a developer-focused identity platform built to make B2B SaaS apps enterprise-ready quickly. It pairs free user management with enterprise features like SSO, Directory Sync, and audit logs, and ships a polished hosted UI through AuthKit.

Key features

• Flexible UI support via APIs and SDKs, with AuthKit as a highly customizable hosted login powered by Radix.
• Enterprise SSO with native SAML and OIDC, configurable by customers through an Admin Portal.
• SCIM provisioning with real-time synchronization to any major identity provider, including Okta, Azure AD, and Google Workspace.
• Tamper-proof audit logs for SOC 2, HIPAA, and GDPR.
• AI-powered CLI: one command handles framework detection, SDK installation, route creation, environment setup, and build validation. Your app goes from zero auth to full AuthKit integration in about two minutes.
• MCP Auth: built-in authentication for MCP servers and AI agents, with delegated access, agent-scoped tokens, and audit trails for agent actions.
• Passkeys, MFA, social logins, magic auth, and more.
• Secure server-side session handling with instant session revocation.
• Radar for suspicious login detection and threat monitoring.
• RBAC and fine-grained authorization with customizable permissions.
• First-class multi-tenancy with organization management, member invitations, and role assignment.
• On-prem deployment support for customers with strict data residency or infrastructure requirements.
• Enterprise SLA and dedicated support.
• Pricing that scales with growth, with $0 for the first 1 million users.

Pricing

• User management: free for up to 1 million MAUs.
• Single Sign-On: $125 per connection per month, with automatic volume discounts that step down as you scale.
• Directory Sync: $125 per connection per month.
• Audit logs: starts at $5 per organization per month.
• Custom domains: $99 per month, flat rate.

Best for

B2B SaaS companies migrating off Firebase Auth because the next stage of growth requires SAML, SCIM, audit logs, and an admin portal that customers' IT teams can manage themselves. The 1 million MAU free tier on user management means you do not pay more than Firebase did until your customer base is well into enterprise territory, and volume discounts on SSO and Directory Sync keep per-connection costs falling as you scale.

Trade-offs

If your app is purely consumer-facing with no enterprise customers on the horizon, WorkOS's enterprise-first primitives will be more than you need today. The upside is that the foundation is already in place the moment your first enterprise deal lands, with no rewrites required.

2. Auth0

Auth0, now part of Okta, is the most established name in authentication. It supports nearly every auth protocol and identity provider, with a mature ecosystem of extensions, integrations, and documentation built up over more than a decade.

Key features

• Universal Login: a hosted login experience with support for a wide range of authentication methods.
• Extensive IdP support: works with every major SAML and OIDC identity provider and supports dozens of social logins.
• Actions: custom JavaScript that runs during the login pipeline for bespoke logic and enrichment.
• Organizations: B2B multi-tenant primitives with SSO connections scoped per organization.
• MFA and passwordless: a broad range of authenticator options, including WebAuthn and passkeys.
• Compliance: SOC 2, HIPAA, ISO 27001, and other certifications available across higher tiers.

Pricing

Auth0 prices by Monthly Active Users with separate ladders for B2C and B2B. B2B Essentials starts at $150 per month for 500 MAUs with up to three enterprise SSO connections. Professional starts at $800 per month for 500 MAUs with up to five connections. Pricing escalates as MAUs grow, and several enterprise features are gated behind higher tiers.

Best for

Teams that want the broadest possible ecosystem and the deepest catalog of integrations, and that are comfortable absorbing MAU-based pricing as they scale.

Trade-offs

• Pricing unpredictability: MAU-based pricing combined with tier-based feature gating can lead to significant cost increases as user bases grow. Essential enterprise features like SAML SSO, SCIM provisioning, and custom domains are often gated behind higher tiers.
• Vendor independence: Auth0 has been part of Okta since 2021. The product's priorities now sit within Okta's broader strategy rather than as an independent roadmap, which is a meaningful consideration for teams buying identity infrastructure on a multi-year horizon.
• Universal Login redirect: the default hosted login flow redirects users away from your app, which can feel heavy-handed compared to embedded auth options.
• Documentation complexity: extensive docs, but navigating advanced scenarios like custom flows and complex multi-tenant configurations takes more effort than newer alternatives.
• SCIM limitations: provisioning is supported primarily for specific enterprise connections, with more configuration constraints than purpose-built B2B alternatives.

3. Supabase Auth

Supabase is the most direct philosophical successor to Firebase in the open-source world. It markets itself explicitly as the open-source Firebase alternative, and its bundled auth, Postgres, storage, and edge functions stack is the most common landing spot for teams whose Firebase pain is really Firestore pain.

Key features

• GoTrue-based auth engine: email/password, magic links, phone OTP, social logins, and MFA.
• Tight Postgres integration: auth tokens flow directly into row-level security policies, enabling fine-grained data access control without a separate authorization layer.
• Open source and self-hostable: deploy on your own infrastructure if data residency or full data sovereignty matters.
• Bundled BaaS: database, storage, edge functions, and real-time subscriptions ship alongside auth, which makes the migration story from Firebase compelling for teams replacing the whole stack.
• Generous free tier with 50,000 MAUs.

Pricing

• Free: up to 50,000 MAUs and basic project resources.
• Pro: starts at $25 per month base, plus usage-based overages.
• Team: higher monthly base with SSO for your own team and additional compliance features.
• Enterprise: custom pricing for SAML SSO on your application, advanced compliance, and dedicated support.

Best for

Startups and growing teams whose Firebase pain is concentrated in Firestore's relational limits and who want a Postgres-first stack with auth included. Particularly strong for teams that value open source and the option to self-host.

Trade-offs

• Limited enterprise SSO: Supabase supports OIDC connections, but deep SAML configuration and per-tenant SSO management for your customers are gated behind the Enterprise tier or require custom work.
• No native organizations or multi-tenancy: Supabase models users at the project level. B2B patterns like "our customers' organizations" are your job to design and maintain via row-level security policies and database schemas.
• No pre-built auth UI: there are auth helpers and starter templates, but no drop-in components comparable to AuthKit. You build sign-in and sign-up flows yourself.
• Value concentrates with the full stack: Supabase Auth works standalone, but most of the appeal is the integration with Supabase Postgres. If you are not adopting the database, the case for Supabase Auth alone weakens.
• No built-in compliance-grade audit logging: activity tracking acceptable to enterprise procurement requires custom implementation.

4. FusionAuth

FusionAuth is a purpose-built authentication platform with the most flexible deployment model in this lineup: fully self-host on your own infrastructure, or run as single-tenant cloud where FusionAuth manages the instance but it is not shared with other customers. Auth is the primary product, not a side feature of a backend platform.

Key features

• Full SAML 2.0 and OpenID Connect support, including identity provider federation.
• MFA, passkeys, magic links, and a deep range of authenticators.
• Multi-tenant by design: tenants are first-class primitives, which makes B2B SaaS patterns more natural than realm-based or project-based alternatives.
• Themes and branding customizable per tenant without a separate UI build.
• Webhook-based extensibility rather than embedded scripting, which keeps the runtime predictable.
• Polished admin UI relative to other self-hostable options like Keycloak.
• Free Community edition self-hosted with no MAU cap.

Pricing

FusionAuth's Community edition is free to self-host with no MAU limits. Paid plans add features like advanced reporting, breached password detection, threat detection, and SLA-backed support, with self-hosted Starter beginning around $125 per month. Managed cloud plans start at similar levels, with single-tenant cloud available as a higher tier. Enterprise pricing is custom.

Best for

Teams with hard data residency, air-gap, or single-tenant cloud requirements that managed-only platforms cannot meet. Common in regulated industries like healthcare, financial services, and government, and for SaaS companies whose largest customers require deployment into the customer's own cloud.

Trade-offs

• Smaller ecosystem and brand recognition compared to Auth0 or Firebase, with fewer third-party integrations and a smaller community of public examples.
• B2B SaaS depth is good but not as opinionated as platforms purpose-built for the "our customers' organizations" model. You still configure tenant-level branding, role mapping, and provisioning yourself.
• Self-hosting is real operational work. Patching, scaling, upgrades, and uptime are your responsibility on the Community edition, and managed cloud costs add up at higher MAU tiers.
• Compliance certifications like SOC 2, ISO 27001, and HIPAA are your responsibility to obtain and maintain on self-hosted deployments.
• Modern features like passkeys, agent-ready auth, and adaptive risk are present but less polished than on managed-first platforms.

5. AWS Cognito

AWS Cognito is Amazon's managed authentication service. It is the natural fit only for teams already deeply committed to AWS who want auth that integrates with API Gateway, Lambda, and IAM out of the box. Outside of that specific context, the developer experience and B2B story are weak enough that other options on this list will serve you better.

Key features

• User pools and identity pools: user pools handle application authentication; identity pools federate access to AWS resources.
• Native AWS integration with API Gateway, Lambda authorizers, AppSync, and the broader AWS service catalog.
• Lambda triggers for customizing pre-signup, post-confirmation, pre-token-generation, and other lifecycle events.
• SAML and OIDC federation for enterprise identity providers.
• Hosted UI for sign-up, sign-in, and password reset flows.
• Pay-as-you-go pricing aligned with the rest of an AWS bill.

Pricing

50,000 free MAUs on the standard tier. Beyond that, pricing is usage-based, with separate, higher rates for federated SAML and OIDC users. Advanced security features like adaptive authentication and compromised credential detection sit behind a paid tier.

Best for

AWS-native teams whose authentication has to live inside the same IAM and networking boundaries as the rest of their infrastructure, and who are willing to absorb the developer experience tradeoffs to get that integration. If that does not describe your team, the other four options on this list will give you a better outcome.

Trade-offs

• Developer experience is widely considered the weakest in this category. The console is dense, the documentation is sprawling, the SDKs are awkward, and the hosted UI looks dated. Most teams leaving Firebase are looking for better DX, not worse.
• B2B multi-tenancy is awkward. The choice between "one user pool with custom attributes" and "one user pool per tenant" forces tradeoffs around quota, configuration drift, and operational overhead that purpose-built B2B platforms avoid entirely.
• Customization runs through Lambda triggers, which means more glue code, more cold-start considerations, and more infrastructure to maintain than declarative alternatives.
• SAML federation is supported but verbose to configure, and the per-federated-user pricing can surprise teams as their enterprise customer count grows.
• The vendor lock-in trade is lateral. You replace Google Cloud coupling with AWS coupling. If multi-cloud or vendor independence is part of why you are leaving Firebase, Cognito does not solve that problem.

Choosing the right Firebase Auth alternative

The best authentication solution depends on your use case, team size, and growth trajectory.

• Choose WorkOS if you are building a B2B SaaS app and need enterprise SSO, SCIM, audit logs, and a hosted admin portal as first-class primitives. Free user management up to 1 million MAUs, volume-discounted SSO and Directory Sync, and on-prem deployment support come out of the box.
• Choose Auth0 if you want the broadest ecosystem and the most mature feature set, and you are comfortable with MAU-based pricing that can escalate as you scale.
• Choose Supabase Auth if your real Firebase pain is Firestore, you want a Postgres-first stack with auth included, and open source matters. Be ready to build B2B multi-tenancy and enterprise SSO yourself unless you are on the Enterprise tier.
• Choose FusionAuth if you have data residency, air-gap, or single-tenant cloud requirements that rule out managed-only platforms. Expect real operational work and self-managed compliance.
• Choose FusionAuth if you need total deployment flexibility. Expect real operational work and self-managed compliance on the self-hosted path.
• Choose AWS Cognito only if you are already deep in AWS and need tight IAM and Lambda integration. For most other use cases, the other four options will give you a better experience.

Frequently asked questions

What should I consider when choosing a Firebase Auth alternative?

The key factors for B2B SaaS are how the platform models organizations and tenants, how enterprise SSO and SCIM are priced as your customer count grows, whether the admin UX is polished enough to hand to your customers' IT teams, and how much engineering work it takes to ship a production-ready sign-in flow. Vendor independence and roadmap predictability are also worth weighing, especially given recent consolidation in the identity space.

Is it difficult to migrate from Firebase Auth to another provider?

Migration takes planning but is well-trodden ground. Firebase exports user records and password hashes (scrypt-based) that most major alternatives can import directly, with bcrypt-hashed legacy hashes also supported. Most teams use a hybrid approach: bulk-import existing users into the new provider, run just-in-time migration for active users, and reconfigure SSO connections on a per-tenant basis. Your customers' IT admins will need to update identity provider settings if you are migrating SSO connections.

Can Firebase Auth alternatives handle enterprise requirements?

Yes. WorkOS, Auth0, and FusionAuth all support SAML SSO, SCIM, audit logs, and MFA at enterprise scale. WorkOS is built specifically to make B2B SaaS apps enterprise-ready quickly, with a free user management tier that extends up to 1 million MAUs and volume discounts on SSO and Directory Sync connections.

Are there any open-source Firebase Auth alternatives?

Yes. Supabase is the most established open-source option and the most direct Firebase-shape replacement, with auth bundled into a full Postgres-based BaaS. FusionAuth's Community edition is also free to self-host and is purpose-built for auth. Other open-source options worth a look include Keycloak (more workforce IAM than B2B SaaS), Ory, and Appwrite (positioned as a self-hosted Firebase clone, though native SAML SSO is not yet supported, which limits its B2B SaaS readiness).

What about Firestore? Do I have to migrate the database too?

No. Firebase Auth and Firestore are technically independent products, and you can migrate auth without touching your database. In practice, though, most Firebase migrations end up being whole-stack migrations because Firestore's relational limits are usually part of why teams are leaving in the first place. Supabase is the most common landing spot for teams replacing both at once. If you only need to replace auth, WorkOS, Auth0, FusionAuth, and Cognito all work alongside any database.

Next steps

WorkOS stands out as the strongest Firebase Auth alternative for B2B SaaS. With a single integration, you can connect your app to every major corporate identity provider and get ready to support your first enterprise customer in hours rather than months.

• Get started fast: SDKs in every popular language, thorough documentation, and Slack-based support let you ship SSO in minutes.
• Support every protocol: OAuth 2.0 integrations with providers like Google and Microsoft, plus full SAML and OIDC support for custom connections, including legacy IdPs.
• Avoid the back-and-forth: the WorkOS Admin Portal lets your customers' IT teams configure SSO and SCIM themselves, without a week of email threads between your team and theirs.
• Pricing that makes sense: free user management up to 1 million MAUs, flat-rate SSO and SCIM connections with automatic volume discounts, and no surprise overages as you scale.

Sign up for WorkOS today, and start selling to enterprise customers tomorrow.