If you’ve ever stared at an unexpected Auth0 overage invoice at 11pm, or spent three days debugging custom role permissions that refused to work, you’re not alone. Identity and access management is the quiet backbone of every modern app, and when your tool doesn’t fit, it drags every other part of your project down. This is exactly why so many teams are researching 7 Alternatives for Auth0 right now, looking for options that match their budget, use case and team size.

For years, Auth0 was the default pick for anyone building user login. It had great documentation, a friendly onboarding flow, and seemed to work for every project. But after the Okta acquisition, pricing tiers shifted, support response times slowed, and many small teams and enterprise users alike started looking elsewhere. You don’t have to stick with a tool that no longer works for you. In this guide, we’ll break down every top competitor, walk through pros, cons, and ideal use cases so you can stop researching and start building.

1. Supabase Auth: Open Source Self-Hosted Or Cloud Option

Supabase Auth is easily the fastest growing Auth0 alternative right now, and for good reason. Built as part of the full open source backend stack, it lets you run everything on your own infrastructure, or use their managed cloud service with predictable flat pricing. Unlike Auth0 which charges per active user, Supabase caps pricing for most small teams, making it ideal for side projects and early stage startups that don’t want surprise bills.

When evaluating Supabase, you’ll notice it comes with all the core features most teams need right out of the box. This includes:

• Email and password login
• Social OAuth for 30+ providers
• Magic links and one time passwords
• Row level security that integrates directly with your database

None of these features are locked behind premium tiers, which is a huge difference from Auth0’s current pricing model.

The biggest tradeoff with Supabase Auth comes for enterprise use cases. Right now, advanced SSO options are still maturing, and custom role management doesn’t have the same granular controls that very large teams require. You also won’t get the same level of dedicated support that Auth0 used to offer, though community forums are active and most common issues have documented fixes.

This tool works best for teams already using or considering Supabase for their database, small to mid sized SaaS products, and any project where predictable pricing is a top priority. If you have under 100,000 monthly active users, Supabase will almost always be cheaper than an equivalent Auth0 plan.

2. Clerk: Modern Developer-First Login Experience

Clerk launched specifically to solve the pain points developers were complaining about with Auth0 starting in 2022. The team built every part of the tool around developer experience, with prebuilt UI components that work across every major frontend framework. Most teams report they can get a full production login flow running in under an hour, compared to 3-5 days for the same setup on Auth0.

Pricing is one of Clerk’s biggest selling points. Unlike Auth0 which raises prices once you cross arbitrary user thresholds, Clerk uses a simple tiered model that stays transparent even at scale.

Plan	Monthly Active Users	Monthly Cost
Free	Up to 10,000	$0
Pro	Up to 100,000	$99
Business	Unlimited	Custom Quote

For reference, that same 100,000 user tier on Auth0 will typically run you over $800 per month.

Clerk isn’t perfect for every team. If you need full self hosting, this is not the tool for you - right now Clerk only offers managed cloud hosting. They also don’t support very niche identity providers that some enterprise customers require, though they add new providers every few months based on user requests.

Choose Clerk if you are building a modern SaaS or consumer app, prioritize fast development time, and don’t need to run your identity system on premise. It is currently the most popular alternative for teams building with React, Next.js and Vue.

3. Keycloak: Enterprise Grade Open Source IAM

Keycloak is the original open source identity management tool, and it remains the most feature complete option on this list. Originally developed by Red Hat, it is now maintained by a huge global community and used by over 50% of Fortune 500 companies for internal and customer facing authentication.

Unlike every commercial tool on this list, Keycloak is 100% free forever. You can run it on any server, for any number of users, with zero licensing fees. The tradeoff is that you will be responsible for hosting, updates and maintenance. Teams that choose Keycloak typically report:

1. 10x lower long term cost compared to Auth0
2. Full control over all user data and infrastructure
3. Support for every standard identity protocol that exists
4. No vendor lock in of any kind

These benefits make it worth the extra work for many teams.

The biggest downside of Keycloak is its learning curve. The default user interface is dated, documentation can be overwhelming for new users, and you won’t get dedicated support unless you pay for a third party hosting provider. Many teams that try Keycloak quit after a week because they don’t anticipate the setup work required.

Keycloak is the best pick for enterprise teams, government projects, and any organisation that needs full control over their identity system. Don’t choose it for small side projects unless you already have experience hosting and maintaining production services.

4. Ory: Modular Open Source Identity Stack

Ory takes a different approach to identity management than most tools. Instead of one monolithic platform, Ory is built as separate modular components that you can mix and match based on what your project needs. You can use just the login system, add permissions later, or run the full stack end to end.

This modular design means you never pay for features you don’t use. Ory offers both self hosted open source versions and a managed cloud service, so you can start in the cloud and move to self hosting later as your project grows. This is one of the only tools that lets you switch deployment models without rewriting all of your integration code.

Ory excels at advanced use cases that most tools cannot handle. Common use cases include:

• Multi tenant SaaS applications with custom login per tenant
• Regulated industries with strict data residency requirements
• Mobile apps that need offline authentication
• Projects that require custom password hashing algorithms

For any of these use cases, Ory will almost always be a better fit than Auth0.

The main drawback with Ory is that it is built for experienced developers. There is no no-code setup, and you will need to write more integration code than you would with Clerk or Supabase. This is not a drop in replacement, but it is the most flexible tool on this list by a wide margin.

5. FusionAuth: Self Hosted Or Managed IAM For Business

FusionAuth was built explicitly as an Auth0 alternative, and they have positioned themselves directly against Okta and Auth0 for mid market and enterprise customers. Unlike most other tools, they do not have a venture capital backed growth model, which means they have kept pricing stable for over 8 years with no unexpected increases.

One of the most popular features of FusionAuth is that you can license the software permanently and run it on your own servers forever. You only pay for updates and support after the first year. This is an almost unheard of pricing model in modern SaaS, and it has earned FusionAuth a very loyal customer base.

When comparing FusionAuth directly to Auth0, the feature parity is almost exact.

Feature	FusionAuth	Auth0
Multi Factor Auth	All Plans	Premium Only
Passwordless Login	All Plans	Premium Only
Custom Domains	Free	$23/month extra
Data Export	Full Unrestricted	Limited Format

Nearly every standard feature that Auth0 locks behind expensive tiers is included in even FusionAuth’s free plan.

FusionAuth does have a steeper learning curve than tools like Clerk, and their frontend components are not as polished. This is a tool built first for reliability and compliance, not developer speed. It works best for business and enterprise teams that value stability over fast setup.

6. Firebase Auth: The Default For Google Ecosystem Teams

Firebase Auth is probably the most widely used identity tool on earth, even if most people don’t talk about it. It is the oldest option on this list, backed by Google, and completely free for up to 50,000 monthly active users. If you are already building on Google Cloud or for mobile apps, this is one of the most reliable options available.

The biggest advantage of Firebase Auth is how well it integrates with the rest of Google’s tools. It works natively with Android, iOS, Google Cloud Functions, Firestore and every other Google service. There are thousands of tutorials, example projects and third party libraries for every platform and framework you could possibly use.

Before you pick Firebase Auth, you should understand the common downsides:

1. Vendor lock in is very strong, you can never export full user credentials
2. Advanced role management is extremely limited
3. Support is almost non existent for free users
4. Pricing scales very quickly once you pass the free tier

None of these are deal breakers for every project, but they are important to know before you start building.

Choose Firebase Auth for mobile apps, side projects, and any team that is already fully committed to the Google ecosystem. It is not a good fit for enterprise SaaS or projects that may need to switch providers later down the line.

7. ZITADEL: Cloud Native Open Source IAM

ZITADEL is the newest tool on this list, and it has quickly gained traction as a modern alternative to Keycloak. Built from scratch for cloud native environments, it runs natively on Kubernetes, has a clean modern API, and supports all modern identity standards.

Like other open source options, you can run ZITADEL completely for free on your own infrastructure, or use their managed cloud service with transparent per user pricing. They also offer unique features like built in audit logging that meets most global compliance requirements, and multi region deployment out of the box.

Many teams switch to ZITADEL after trying Keycloak and finding it too old and difficult to maintain. Common reasons teams choose ZITADEL include:

• Native Kubernetes support and horizontal scaling
• Modern developer friendly API and documentation
• Built in multi tenant support
• Active full time development team

These features make it the best new open source option released in the last 5 years.

The only downside right now is that ZITADEL has a smaller user base than older tools, so you will find fewer third party tutorials and community answers. That said, the official support team is very responsive, and most bugs get fixed within days of being reported. This is a great pick for teams that want open source without the legacy baggage of older tools.

At the end of the day, there is no perfect identity management tool, and none of these 7 alternatives for Auth0 will be right for every single team. The best choice will always depend on your team size, budget, technical ability, and specific project requirements. Small startups should prioritize speed and predictable pricing, while enterprise teams will usually value control and compliance above everything else.

Don’t rush this decision. Test the top 1 or 2 options that match your use case with a small group of users before you commit to migrating your whole user base. Most of these tools offer free plans that let you run a full test deployment without any upfront cost. Once you find the right fit, you’ll wonder why you put up with the frustrations of your old tool for so long.