Free Authentication Providers
Which authentication providers a startup can add to its app for free today, how many monthly active users the free tier covers, whether it includes enterprise SSO, whether a card is needed and what the first paid plan costs, read from each provider's own page.
Free allowances read on each provider's own pages, all checked on or after . Auth providers change their free tiers and user caps from time to time: confirm the terms on the provider's page before you build sign-in around it.
Authentication providers you can add to your app for free today include Authgear (Unlimited MAUs, up to 2 apps), Keycloak (Open source (Apache-2.0 license)), WorkOS (1 million monthly active users), authentik (Free open source edition), and Logto (50,000 monthly active users). Each of the 16 free tiers below links to the provider's page that states it, with its main limit, whether it includes enterprise SSO, whether a card is needed and what the first paid plan costs.
Sign-up, sign-in and user management are among the first things a product needs and the last things a small team wants to build. Hosted auth services handle them for you, open-source identity servers let you run them yourself, and most have a free tier.
The headline rarely tells you how far it goes. A free tier can stop at a number of monthly active users and keep MFA, organizations or enterprise SSO for paid plans. Each provider below shows what is free, its main limit, whether it includes enterprise SSO, whether a card is needed and what the first paid plan costs, quoted from the provider's own page with the date we read it.
Which providers we picked and the order they appear in are our editorial choices; the terms are the providers'. Some of these providers pay us a referral commission when someone signs up through our link: those links are labeled, and they play no part in which providers are listed or where.
Hosted authentication services with a free tier
Services that run sign-up, sign-in and user management for your app, with a free tier up to a number of monthly active users.
- 1
Authgear
Unlimited users on a free plan
Authgear's Free plan has unlimited MAUs, up to 2 applications and 100 SMS or WhatsApp messages, with no credit card required. Every plan includes every feature, and the Developers plan is $50 a month.
- Enterprise SSO
- Yes, every plan has every feature (source: authgear.com)
- Payment card
- No credit card required (source: authgear.com)
- First paid plan
- Developers: $50 a month (source: authgear.com)
- 2
WorkOS
Free user management for up to 1M users
WorkOS User Management is free for up to 1 million monthly active users, and you need no credit card until production. SSO connections are paid, from $125 each, and each extra 1 million users costs $2,500 a month.
- Enterprise SSO
- Paid: $125 per connection (1-15) (source: workos.com)
- Payment card
- No card until production (source: workos.com)
- First paid plan
- Per extra 1M users: $2,500 a month (source: workos.com)
Start free at WorkOSTerms read on workos.com on WorkOS: the free allowance and how to start WorkOS for Startups: what startups get - 3
Logto
Open-source auth with a large free user cap
Logto's Free plan covers up to 50,000 monthly active users with no credit card required, and includes 3 social connectors. Its Pro plan starts at $24 a month.
- Payment card
- No credit card required (source: logto.io)
- First paid plan
- Pro: from $24 a month (source: logto.io)
- 4
Supabase Auth
Auth for an app built on Supabase
Supabase Auth is included on the free plan for up to 50,000 monthly active users. Single sign-on (SAML 2.0) is not included on Free, and the Pro plan starts at $25 a month.
- Enterprise SSO
- Not included on the Free plan (source: supabase.com)
- First paid plan
- Pro: from $25 a month (source: supabase.com)
Start free at SupabaseTerms read on supabase.com on Supabase Auth: the free allowance and how to start - 5
Clerk
Prebuilt sign-in UI for a small app, free
Clerk's Hobby plan is free with no credit card, for 50,000 monthly retained users per app, but its sessions are fixed at 7 days and SSO is not included. Pro starts at $25 a month, or $20 billed annually.
- Main limit
- Fixed 7-day sessions (source: clerk.com)
- Enterprise SSO
- Not included on Hobby (source: clerk.com)
- Payment card
- No credit card required (source: clerk.com)
- First paid plan
- Pro: $25 a month, or $20 billed yearly (source: clerk.com)
Start free at ClerkTerms read on clerk.com on Clerk: the free allowance and how to start Clerk for Startups: what startups get - 6
Auth0
Enterprise-grade login with a large free tier
Auth0's Free plan covers up to 25,000 monthly active users with no credit card needed to sign up, and includes one enterprise connection. Its Essentials plan is $35 a month.
- Enterprise SSO
- 1 enterprise connection (source: auth0.com)
- Payment card
- No card needed to sign up (source: auth0.com)
- First paid plan
- Essentials: $35 a month (source: auth0.com)
Start free at Auth0 (Okta)Terms read on auth0.com on Auth0: the free allowance and how to start Auth0 for Startups: what startups get - 7
Stytch
Auth with 5 free SSO or SCIM connections
Stytch's pay-as-you-go plan is always free up to 10,000 monthly active users and 5 SSO or SCIM connections, with 1,000 M2M tokens. Past those amounts you pay for usage, at $125 per extra connection.
- Enterprise SSO
- 5 SSO or SCIM connections (source: stytch.com)
- First paid plan
- Usage past free: $125 per connection (source: stytch.com)
Start free at StytchTerms read on stytch.com on Stytch: the free allowance and how to start Stytch Startup Program: what startups get - 8
Kinde
Free login with SSO and no card needed
Kinde's Free plan covers 10,500 monthly active users with no credit card required, and includes one enterprise SSO connection. Its first paid plan, Pro, is $25 a month.
- Enterprise SSO
- 1 enterprise SSO connection (source: kinde.com)
- Payment card
- No credit card required (source: kinde.com)
- First paid plan
- Pro: $25 a month (source: kinde.com)
Start free at KindeReferral linkTerms read on kinde.com on Kinde: the free allowance and how to start - 9
Frontegg
B2B apps that need SSO connections early
Frontegg's pay-as-you-go plan costs $0 a month and includes 7,500 monthly active users and 5 enterprise SSO/SCIM connections. Enterprise is custom-priced.
- Enterprise SSO
- 5 enterprise SSO/SCIM connections (source: frontegg.com)
- 10
Descope
Passwordless and SSO apps before they grow
Descope's Free Forever plan covers 7,500 monthly active users and 3 SSO connections with no overages, so you move to Pro rather than being billed. The Pro plan starts at $249 a month.
- Enterprise SSO
- 3 SSO connections (source: descope.com)
Start free at DescopeTerms read on descope.com on Descope: the free allowance and how to start Descope Hello World Startup Plan: what startups get - 11
PropelAuth
Auth for up to 10,000 monthly users, free
PropelAuth's Free plan includes 10,000 monthly active users. SAML SSO starts on the Growth plan, at $150 a month.
- Enterprise SSO
- No, SAML SSO starts on Growth (source: propelauth.com)
- First paid plan
- Growth: $150 a month (source: propelauth.com)
Start free at PropelAuthTerms read on propelauth.com on PropelAuth: the free allowance and how to start
Open-source authentication you run yourself
Identity servers you host on your own infrastructure: no user cap from a vendor, but you run and secure them.
- 1
Keycloak
Self-hosted SSO with SAML and OIDC
Keycloak is open source under the Apache-2.0 license, and can authenticate users with existing OpenID Connect or SAML 2.0 identity providers.
- 2
authentik
Self-hosted SSO with SAML, OIDC and LDAP
authentik's open-source edition is free and supports OIDC, SAML, LDAP and SCIM, with community support only. Its Enterprise plan is $5 per user a month.
- First paid plan
- Enterprise: $5 a user a month (source: goauthentik.io)
Start free at authentikTerms read on goauthentik.io on authentik: the free allowance and how to start - 3
FusionAuth
Self-hosted auth with no user cap
FusionAuth Community is free and unlimited. Advanced MFA and theming need the Starter plan, from $162 a month billed annually.
Start free at FusionAuthTerms read on fusionauth.io on FusionAuth: the free allowance and how to start - 4
SuperTokens
Self-hosted with no MAU limit, or a free cloud under 5K
SuperTokens' open-source features are free to self-host without any limits. Its managed cloud is free under 5,000 monthly active users, then $0.02 per MAU.
- First paid plan
- Cloud: $0.02 per MAU above 5K (source: supertokens.com)
Start free at SuperTokensTerms read on supertokens.com on SuperTokens: the free allowance and how to start - 5
Casdoor
Open-source IAM and SSO you host yourself
Casdoor is free and open source, and speaks OAuth 2.0, OIDC, SAML 2.0 and LDAP. Its Cloud option uses flat monthly pricing, with no per-user fees.
- What's free
- Free and open source (source: github.com)
- Enterprise SSO
- SAML 2.0, OIDC, LDAP and CAS (source: github.com)
Authentication startup programs
Programs from authentication providers that give startups credits or a discount on paid plans. Most ask for an application.
Also useful for authentication and security
Referral links, picked for fit and ordered by fit (70%) and what a signup earns us (30%), at no cost to you. They never change this page's ranking.
Compare the top options
How this comparison is built
The list covers hosted authentication services and open-source auth a founder can use for free today without applying to a program. The order and the "best for" notes are our editorial reading of each provider's terms. Every term comes from the provider's own pricing or help page on the date shown, never from a third-party list; follow each link for the full conditions. A cap on monthly active users, MFA, organizations or enterprise SSO kept for paid plans can matter more than the headline, so the comparison quotes them wherever the provider states them. Some of these providers pay StartupPerks a referral commission, and their links are labeled as referral links; that decides neither whether nor where a provider appears, and no provider pays for a placement on this page.
Read the full methodologyCommon questions
What is the best free authentication provider?
It depends on your user count and whether you need enterprise SSO. By the terms each provider states, Clerk's free plan covers 50,000 monthly retained users per app, Supabase Auth and Logto 50,000 monthly active users, Auth0 up to 25,000 with one enterprise connection, and Kinde 10,500 with one enterprise SSO connection. WorkOS covers 1 million monthly active users and charges per SSO connection.
What are Clerk's free tier limits?
Clerk's free Hobby plan covers 50,000 monthly retained users per app with fixed 7-day sessions; enterprise SSO is not included. Pro costs $25 a month, or $20 billed yearly.
What are Auth0's free tier limits?
Auth0's free plan covers up to 25,000 monthly active users and includes one enterprise connection; a custom domain needs card verification. Essentials starts at $35 a month.
Which free auth plans include enterprise SSO?
Auth0 includes 1 enterprise connection, Kinde 1 enterprise SSO connection, Descope 3 SSO connections, and Stytch and Frontegg 5 SSO or SCIM connections each. Clerk's and Supabase Auth's free plans do not include enterprise SSO.
Can I self-host authentication for free?
Yes. Keycloak, authentik and Casdoor are open source, FusionAuth's Community edition is free and unlimited when you host it yourself, and SuperTokens is free to self-host with no limits. You run, update and secure the server yourself.
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