Amazon Cognito vs. Auth0: Why Cognito is a Nightmare
If you’ve ever tried to integrate Amazon Cognito, you’ve probably hit a wall—multiple times. On paper, it looks like a great choice: deep AWS integration, low cost, and support for OAuth, OpenID, and SAML. In practice? It’s an underfunded, barely maintained product with awful documentation, hidden pitfalls, and a frustrating developer experience.
Then there’s Auth0, which is the complete opposite: well-documented, feature-rich, and easy to use. But as you scale, its pricing explodes, forcing companies to reconsider their decision.
So which one should you use? If your goal is to get authentication up and running with minimal pain, avoid Cognito. Here’s why.
Cognito: The Identity Service That AWS Forgot
Amazon Cognito has been around for years, yet it still feels like a half-baked AWS service that no one at Amazon actually uses.
1. The Documentation is a Mess
Trying to implement Cognito with AWS SDKs often feels like a guessing game. The documentation is outdated, incomplete, and scattered across multiple AWS pages. Developers routinely turn to Stack Overflow and Reddit because even AWS Support struggles to explain how certain features work.
A common sentiment:
“The only way to get Cognito working properly is to find another project’s IaC and copy it.”
2. Good Luck Customizing It
Cognito’s Hosted UI is laughably bad—an ancient, uncustomizable login page that looks like something from the early 2000s. Want to tweak the UI beyond changing colors and a logo? Too bad. You’ll need to build a custom authentication flow from scratch.
And if you need multi-region failover? Forget it. Cognito doesn’t properly replicate user data across regions, which means if your primary AWS region goes down, your users won’t be able to log in.
3. Hidden Gotchas Everywhere
Cognito is full of unexpected limitations:
- Once you set a field as required, you can’t change it later without recreating the entire user pool.
- MFA data can’t be exported, meaning if you migrate away, you lose it.
- API keys? Cognito’s solution is an undocumented, hacky mess.
- Features like refresh token rotation—standard in other providers—are still missing in 2024.
Auth0: The Gold Standard (If You Can Afford It)
Auth0 is the go-to identity provider for many startups and enterprises because it just works. Unlike Cognito, it has:
- Excellent documentation with clear examples.
- A modern, customizable UI that doesn’t require rebuilding everything from scratch.
- A vast ecosystem of integrations with third-party services.
- Reliable multi-region support to keep logins working even during outages.
But there’s a catch: pricing.
Auth0 starts off cheap, but as you scale, it gets ridiculously expensive—especially for B2B applications. Features like OTP-based MFA can push costs into the hundreds or even thousands per month, making it hard to justify for small teams.
One developer summed it up perfectly:
“Auth0 is amazing until you get the bill.”
Note that Auth0 has a start-up plan you can apply to that gets you a significant discount for the first year as a start-up.
So, What’s the Right Choice?
If your budget is tight and your team is deep into AWS, Cognito might seem tempting. But be prepared to invest a ton of development time into making it work. For most teams, that time would be better spent just using Auth0 or another provider.
If you want an auth solution that works out of the box, Auth0 is the clear winner—as long as you can afford it. If not, alternatives like Firebase Authentication, Keycloak, or even rolling your own might be worth considering.
But if you choose Cognito? Just be ready for a long, frustrating ride.
