Question 1

Should I build authentication myself?

Accepted Answer

No. Authentication is security-critical with many edge cases: password hashing, session management, rate limiting, 2FA. Services like Clerk and Auth0 have teams dedicated to getting this right. Use them.

Question 2

Clerk, Auth0, or Supabase Auth?

Accepted Answer

Clerk has the best developer experience and modern UI components. Auth0 is enterprise-grade with extensive features. Supabase Auth is great if you're already using Supabase. Clerk is the popular choice for new startups.

Question 3

What does authentication cost?

Accepted Answer

Most services have generous free tiers. Clerk is free up to 10,000 monthly active users. Auth0 is free up to 7,000 users. Supabase Auth is free with their database. Paid plans scale with user count.

Question 4

What is the difference between authentication and authorization?

Accepted Answer

Authentication verifies who users are (login). Authorization determines what they can do (permissions). Auth services handle authentication. You typically build authorization logic in your app based on user roles.

Question 5

What social login providers should I support?

Accepted Answer

Start with Google—it has the widest reach. Add GitHub for developer products. Apple Sign-In is required for iOS apps. Facebook if your audience uses it. Don't over-add—each provider has maintenance overhead.

Question 6

What are magic links?

Accepted Answer

Passwordless login via email links. Users enter their email, receive a link, click it, and they're logged in. More secure than passwords, better UX for many users. Most auth services support magic links.

Question 7

How does OAuth work?

Accepted Answer

OAuth lets users log in with existing accounts (Google, GitHub). Your app redirects to the provider, user approves, provider sends back a token. Auth services abstract this complexity—you just configure the providers.

Question 8

Should I require two-factor authentication?

Accepted Answer

Offer it, but don't require it for all users—it adds friction. Require 2FA for admin accounts and sensitive operations. Auth services make 2FA easy to implement with TOTP apps or SMS.

Question 9

How do I handle password resets?

Accepted Answer

Never build password reset yourself—it's a common vulnerability source. Auth services handle secure reset flows: send token via email, expire quickly, one-time use. Just configure the email templates.

Question 10

What is session management?

Accepted Answer

Tracking logged-in users across requests. Sessions can be JWT tokens or server-side. Auth services handle session creation, validation, and expiration. Configure session duration based on your security needs.

Question 11

How do I add authentication to my React/Next.js app?

Accepted Answer

Clerk and Auth0 provide React SDKs with hooks and components. Wrap your app in their provider, use their login components or hooks. Protected routes check auth state. Documentation walks through setup.

Question 12

What about mobile app authentication?

Accepted Answer

Same providers work for mobile. Auth0, Firebase, and Clerk have iOS and Android SDKs. Handle token storage securely on device. OAuth flows work slightly differently on mobile but SDKs abstract this.

Question 13

How do I migrate from one auth provider to another?

Accepted Answer

Painful but possible. Export user data (if provider allows), import to new provider, handle password migration (usually requires reset), and update your code. Plan carefully and migrate during low-traffic periods.

Question 14

What is WorkOS for?

Accepted Answer

WorkOS focuses on enterprise features: SSO (Single Sign-On), directory sync, and compliance. If you're selling to enterprises that require SSO with their identity provider (Okta, Azure AD), WorkOS handles it.

Question 15

How do I test authentication in development?

Accepted Answer

Auth services provide test modes and development environments. Create test users, use sandbox OAuth apps, and separate dev from production. Clerk and Auth0 have great local development workflows.

Question 16

What are webhooks and why do I need them for auth?

Accepted Answer

Webhooks notify your app when auth events occur: user created, updated, deleted. Use them to sync user data to your database, send welcome emails, or trigger onboarding flows. Essential for keeping systems in sync.

Question 17

How do I handle user data with GDPR?

Accepted Answer

Auth providers store user data in their infrastructure. Ensure your provider is GDPR-compliant. Implement data export and deletion features as required. Clerk and Auth0 provide user data APIs for compliance.

Question 18

What is rate limiting and why does auth need it?

Accepted Answer

Rate limiting prevents brute force attacks by limiting login attempts. Auth services handle this automatically—blocking IPs after failed attempts. Without it, attackers could try unlimited passwords.

I need user authentication for my app

About This Problem

You might have this problem if:

Success Looks Like

Relevant For

Recommended Tools

Clerk

Auth0

Supabase

Firebase

WorkOS

Frequently Asked Questions

Related Problems

I need to manage team passwords securely

I need a database for my application

Help us improve this page

Stay in the loop