Firebase Authentication Alternatives in 2026: 8 Platforms Compared

Firebase Authentication is the fastest way to a working consumer login, and it stops being enough at a predictable moment. The first enterprise customer asks for SAML SSO. Or you need real tenant boundaries. Or you decide to leave Google Cloud and auth is the last thing holding you there. If you like the bundled model but want off GCP, pick Supabase Auth. If you now need B2B Organizations and enterprise SSO, Auth0. If the pain is developer experience on React or Next.js, Clerk. If you want hyperscaler-native on AWS, Amazon Cognito. For passwordless consumer login, MojoAuth.

One thing to strike from any older shortlist: Azure AD B2C has not been sold to new customers since 1 May 2025. It is still recommended in most Firebase comparisons on the web. It is not an option you can buy. Microsoft's replacement is Entra External ID, covered below.

How we evaluated

Every price and plan limit here was read off the vendor's own pricing page or documentation in September 2026, not lifted from another comparison post. End-of-sale and acquisition claims were checked against the vendor's own announcement.

Deepak Gupta founded LoginRadius and scaled it past a billion managed identities. The axes below are the four that decide real CIAM migrations: what breaks first as you grow, how cost behaves with active users, whether enterprise SSO is a feature or a paywall, and whether password hashes move without a reset. Firebase is unusually good on that last point, covered at the end.

Last verified: September 2026. Checked this pass: Firebase and Identity Platform pricing, the eight alternatives' pricing pages, Azure AD B2C end-of-sale status, and current Keycloak release status.

What Firebase Authentication costs now

Standard Firebase Authentication is free to 50,000 monthly active users on both the Spark and Blaze plans. With the Identity Platform upgrade on Blaze, MFA and multi-tenancy become available, but SAML and OIDC authentication is free only to 50 MAU and then follows Google Cloud pricing. Phone authentication bills per SMS at region-dependent rates.

That 50 MAU SAML allowance is the number worth internalising. Firebase does not price enterprise federation as a growth feature; it prices it as an exception. That is the ceiling most teams hit.

Quick comparison

Platform	Pricing (Sept 2026)	Ceiling it lifts	Main trade-off
Supabase Auth	Free to 50,000 MAU; Pro $25/mo to 100,000 MAU; $0.00325 per extra MAU	GCP coupling, with the same bundled model	Still B2C-leaning; does not solve enterprise SSO
Auth0	Free to 25,000 MAU; B2C Essentials from $35/mo, Professional from $240/mo; B2B from $150/mo	B2B Organizations and enterprise SSO	Cost climbs steeply past 100,000 MAU
Clerk	Free to 50,000 MRU; Pro $25/mo; $0.02 per extra user; $75/mo per enterprise connection	Developer experience, light B2B, off GCP	Directory Sync is thinner than a dedicated B2B platform
Amazon Cognito	Lite free to 10,000 MAU then $0.0055; Essentials free to 10,000 then $0.015; Plus $0.020	Hyperscaler-native, but on AWS	Developer experience lags the modern platforms
MojoAuth	Free to 25,000 MAU; Business Pro from $50/mo	Passwordless and passkey-first login	No SCIM provisioning
Keycloak	Free, Apache 2.0; infrastructure and staff only	Vendor independence and zero licence cost	You own upgrades, theming, and uptime
Okta	Workforce SSO from $6/user/mo; Customer Identity enterprise base $3,000/mo	Enterprise governance and lifecycle	Priced for enterprises, not consumer apps
Microsoft Entra External ID	Usage-based per MAU; quoted	Microsoft-shop consumer identity	Trades GCP gravity for Microsoft gravity

Why teams leave Firebase Authentication

B2C only. There is no genuine B2B Organizations or multi-tenant model. The moment you sell to businesses that need their own tenant boundaries, roles, and admin, you are building that yourself on top of Firebase.

No first-class enterprise SSO. Identity Platform adds SAML and OIDC, but priced free only to 50 MAU, and without the Organizations model that makes B2B SSO usable. The first enterprise deal that requires SSO is the standard trigger for this migration.

GCP coupling. Firebase Auth is wired into Google Cloud. If you move Firestore, Cloud Functions, or hosting elsewhere, auth becomes the anchor that keeps you there.

The Identity Platform upgrade is not the fix. It adds MFA and multi-tenancy, and it also adds pricing and configuration complexity, without closing the Organizations gap against a dedicated B2B CIAM.

Pain to pick

If your problem is	Look at
You want the bundled model, but not on GCP	Supabase Auth
A customer is demanding enterprise SSO	Auth0
Developer experience feels dated, you are on React	Clerk
Your stack is AWS, not GCP	Amazon Cognito
Passwordless and passkeys at consumer scale	MojoAuth
Vendor independence and zero licence cost	Keycloak
Governance, lifecycle, and audit requirements	Okta
The organisation is Microsoft-centric	Entra External ID

1. Supabase Auth: the Firebase model on Postgres

Supabase Auth keeps what teams like about Firebase, auth bundled with the backend and a fast start, on a Postgres foundation with row-level security and an open source core you can self-host. It is the closest like-for-like replacement, and the one with a real exit option.

Pricing (verified September 2026). The Free plan includes 50,000 MAU, matching Firebase. Pro is $25 per month with 100,000 MAU included, Team is $599 per month with the same 100,000 MAU, and overage on both is $0.00325 per MAU. Stored users are unlimited; the cap is on monthly active authentication.

Watch out. Like Firebase, it is B2C-first. It lifts the GCP-coupling ceiling and the data-ownership ceiling. It does not by itself solve an enterprise SSO requirement. Head to head: Firebase Auth vs Supabase Auth.

2. Auth0: when an enterprise customer demands SSO

Auth0 carries a deep B2B Organizations model, SAML and OIDC enterprise connections, a large federation catalog, and the extension model Firebase lacks. This is the standard destination when the trigger is a sales requirement rather than a technical preference.

Pricing (verified September 2026). The free tier covers 25,000 MAU, which is smaller than Firebase's. B2C Essentials starts at $35 per month and Professional at $240. B2B Essentials, which is the tier you actually need for Organizations and enterprise connections, starts at $150 per month, with Professional from $800. Enterprise is quoted.

Watch out. This fixes the feature ceiling, not the cost one. Auth0 gets materially more expensive than Firebase at consumer volume, and the curve steepens past 100,000 MAU. Size the bill at your real MAU first, then read the full Auth0 alternatives comparison so you know what the next migration would look like. Head to head: Auth0 vs Firebase Auth.

3. Clerk: modern developer experience with light B2B

Clerk ships prebuilt, themeable auth components, organizations for light B2B multi-tenancy, and a developer experience tuned to React and Next.js, with no Google Cloud dependency. It lifts the experience ceiling and the coupling ceiling at once, and adds basic B2B that Firebase does not have.

Pricing (verified September 2026). Clerk bills Monthly Retained Users. The Hobby plan is free to 50,000 MRU per app, matching Firebase's free tier. Pro is $25 per month ($20 annual) and Business is $300 per month. Overage runs $0.02 per user between 50,001 and 100,000, sliding to $0.012 at ten million. Pro includes one enterprise connection; extra SAML, OIDC, or EASIE connections are $75 per month each, falling to $15 at very high counts.

Watch out. Organizations are lighter than a dedicated B2B CIAM, and Directory Sync is not the product it is at WorkOS. Heavy enterprise requirements outgrow it. Head to head: Firebase Auth vs Clerk.

4. Amazon Cognito: hyperscaler-native, on the other cloud

Cognito is the AWS-native counterpart to Firebase: user pools, OIDC and SAML federation, Lambda triggers, MFA, and identity inside the same account and IAM model as the rest of your infrastructure. On several enterprise axes it leads Firebase.

Pricing (verified September 2026, and the old numbers are wrong). The 50,000 free MAU tier most comparisons still quote was replaced in November 2024. Current Cognito pricing has three tiers. Lite is free to 10,000 MAU, then $0.0055 per MAU for the next 90,000 and $0.0046 above. Essentials, the default for new pools, is free to 10,000 MAU then $0.015. Plus has no free tier at $0.020 per MAU. SAML and OIDC federation is billed separately at $0.015 per MAU above a 50 MAU allowance. Pools created before 22 November 2024 on Lite can keep the legacy free tier under documented conditions.

Watch out. The developer experience is rougher than Firebase's: a constrained hosted UI, Lambda-trigger debugging, and the User Pool versus Identity Pool split. Cognito also cannot export reusable password hashes, so a future migration off it is harder than a migration off Firebase. See the full Cognito alternatives comparison before you make it your long-term home. Head to head: Cognito vs Firebase Auth.

5. MojoAuth: passwordless and passkeys as the default

MojoAuth is a passwordless-first CIAM: email, SMS and WhatsApp OTP, magic links, and passkeys via WebAuthn, behind a hosted login page or SDKs. For a consumer product where sign-up completion is the metric, it removes the password flows Firebase still centres on.

Pricing (verified September 2026). The free tier covers 25,000 MAU permanently with email OTP, magic links, social login, and basic attack protection. Business Pro starts at $50 per month for 5,000 MAU and adds passkeys, phone OTP, custom domain branding, MFA, team management, and SSO. Enterprise private cloud is quoted with dedicated infrastructure and a 99.99 percent uptime SLA. Startups and non-profits get 50 percent off annual billing.

Watch out. No SCIM provisioning, so it does not cover an enterprise directory-sync requirement. Head to head: Firebase Auth vs MojoAuth.

6. Keycloak: the open source escape hatch

Keycloak covers everything Firebase does for authentication and adds what it lacks: SAML 2.0, LDAP and Active Directory federation, identity brokering, deep theming, and SPI extension points. Apache 2.0, no per-MAU cost at any scale.

Release status (verified September 2026). Keycloak 26.7.4 shipped on 16 September 2026. The project has no long-term-support line: only the newest release receives security fixes, so continuous upgrades are part of the deal.

Watch out. Self-hosting replaces an invoice with an on-call rota. Budget roughly half to one engineer. You also lose the Firebase ecosystem integration with Firestore and Cloud Functions, which is often the real reason teams stay.

7. Okta: when governance arrives

Okta is the enterprise IAM option: lifecycle management and provisioning, adaptive MFA, Universal Directory, API access management, a very large integration catalog, and the compliance evidence enterprise buyers ask for.

Pricing (verified September 2026). Okta publishes Workforce SSO at $6 per user per month on Starter and $17 on Essentials, billed annually. Customer Identity carries a $3,000 per month enterprise base platform fee billed annually, with usage-based add-ons quoted on total annual MAU. Okta also owns Auth0, so shortlisting both is one vendor relationship.

Watch out. If you are a consumer app moving off Firebase for cost or experience reasons, Okta is the wrong shelf. It is right when audit, governance, and lifecycle requirements are the driver.

8. Microsoft Entra External ID (and what happened to Azure AD B2C)

Most Firebase comparisons still list Azure AD B2C. Do not shortlist it: Microsoft stopped selling Azure AD B2C to new customers on 1 May 2025. The successor is Microsoft Entra External ID, which brings consumer and partner identity into the Microsoft cloud with Entra administration, Conditional Access, identity protection, and federation.

It is the right answer when your organisation is already standardising on Microsoft 365 and Azure and you want external identity in the same tenant. It is the wrong answer if you are leaving Firebase specifically to avoid platform gravity, because it swaps Google's for Microsoft's. B2C's Identity Experience Framework custom policies were also notoriously hard to maintain, and that history is worth knowing before you commit to the Microsoft path. Head to head: Entra External ID vs Firebase Auth.

Migrating off Firebase without forcing password resets

This is the good news. Firebase exports password hashes, a modified scrypt with per-project parameters, and most target platforms can import them. Users keep their existing passwords and never see a reset prompt, which is not true of a Cognito migration.

The step that decides success is the hash-parameter mapping. Firebase's scrypt uses project-specific signer key, salt separator, rounds, and memory cost values, which you export from the Firebase console alongside the user records. Get those into the target exactly and verification works on first login. Get them wrong and every login fails silently, which is why you validate against a test account before you cut over.

If a target cannot import Firebase hashes, the fallback is lazy migration: authenticate against Firebase on first login to the new platform, then re-hash locally. Either way, export user attributes, provider links, and custom claims separately, and re-implement any Cloud Functions auth triggers on the new platform's extension model. That inventory sets the timeline more than the SDK swap does.

See the password hash migration guide and Auth Migration Hell for the failure modes.

How to choose

Name the ceiling first, then pick. If you want the bundled model without Google Cloud, Supabase Auth. If a named customer is demanding SSO, Auth0. If the pain is developer experience and you are on React or Next.js, Clerk. If your infrastructure is moving to AWS, Cognito. If login conversion is the metric, MojoAuth. If the goal is independence from every hyperscaler, Keycloak.

For the full scored matrix across every vendor on one set of axes, see the CIAM Compass Firebase profile, the CIAM providers directory, and the complete guide to CIAM if you are new to the category.

Frequently Asked Questions

What is the best alternative to Firebase Authentication?

It depends which ceiling you hit. For the same bundled model on Postgres and open source, Supabase Auth. If you now need B2B Organizations and enterprise SSO, Auth0. For modern developer experience off Google Cloud, Clerk. For hyperscaler-native on AWS, Amazon Cognito. For passwordless and passkey-first consumer login, MojoAuth. For zero licence cost and full control, Keycloak.

Does Firebase Authentication support enterprise SSO?

Not in a way you can sell on. The paid Identity Platform tier adds SAML and OIDC, but the free allowance is 50 monthly active users and there is no real B2B Organizations model behind it. Firebase prices enterprise federation as an exception rather than a growth path. If an enterprise customer requires SSO with their own tenant boundary, that is the signal to move to Auth0, WorkOS, or a comparable B2B CIAM.

Can I migrate Firebase users without forcing a password reset?

Usually yes. Firebase exports password hashes using a modified scrypt with per-project parameters, and most target platforms can import them so users keep their credentials. The step that decides the outcome is mapping the signer key, salt separator, rounds, and memory cost correctly. Validate with a test account before cutover, because a wrong parameter fails every login silently.

Should I still consider Azure AD B2C as a Firebase alternative?

No. Microsoft stopped selling Azure AD B2C to new customers on 1 May 2025. Any comparison recommending it is out of date. The current Microsoft option for customer identity is Entra External ID, which is worth evaluating only if your organisation is already standardising on Microsoft 365 and Azure.

Which Firebase alternative is cheapest at scale?

Keycloak, if you can staff it: Apache 2.0, no licence fee, no per-user charge at any volume. The cost moves to infrastructure and roughly half to one engineer. Among managed options, Supabase Auth includes 50,000 MAU free and then charges $0.00325 per MAU, which is the lowest published per-user rate here. Firebase itself remains cheapest for plain consumer authentication; the comparison only changes once you need the enterprise features it lacks.

Is Supabase Auth a true Firebase Authentication replacement?

For the core job, yes. It covers email and password, social login, magic links, MFA, and identity federation, on a Postgres database with row-level security instead of Firestore. It adds an open source core you can self-host, which Firebase does not offer. What it does not replace is the surrounding Firebase ecosystem, Firestore, Cloud Functions, Remote Config, and it is B2C-first, so it does not close the enterprise SSO gap on its own.