About 18; min
Auth0 and Clerk both handle authentication so you don’t have to build login, signup, and user management from scratch. But they target different developers: Auth0 is the enterprise standard with maximum configurability, while Clerk focuses on modern frameworks with a developer-first experience.
The pricing difference matters more than you’d think. Here’s what each one actually costs when your app starts growing.
Quick Pricing Comparison
| Plan | Auth0 | Clerk |
|---|---|---|
| Free | 7,500 MAU | 10,000 MAU |
| Starter/Pro | $35/mo (500 MAU, then $0.07/MAU) | $25/mo (10K MAU, then $0.02/MAU) |
| Enterprise | Custom (~$1,500+/mo) | Custom |
Clerk is significantly cheaper at every scale. But Auth0 supports more authentication methods, enterprise compliance features, and has a decade of battle-testing in production.
Auth0 Pricing Breakdown
Auth0’s free tier at 7,500 MAU is generous for testing and early-stage products. The pricing gets complicated on paid plans: Essentials starts at $35/month for 500 MAU, with overage at $0.07 per additional MAU. At 10,000 MAU, that’s $35 + (9,500 × $0.07) = $700/month.
Professional at $240/month includes only 1,000 MAU with a higher overage rate of $0.15/MAU. At 10,000 MAU on Professional: $240 + (9,000 × $0.15) = $1,590/month. The Professional plan is meant for teams that need roles, permissions, and machine-to-machine tokens — not for saving money on MAU costs.
Auth0’s Hidden Costs
- Machine-to-Machine (M2M) tokens: Free plan gets 1,000/month. API-heavy apps burn through these fast. Additional M2M tokens cost extra
- Enterprise connections (SAML/LDAP): Not available on Free or Essentials. Professional or Enterprise only
- MFA: Included on Essentials+, but adaptive MFA (risk-based) is Enterprise only
- Custom domains: Essentials and above. Free tier uses Auth0-branded login pages
- Actions (serverless hooks): Free plan limited to 3 Actions. Essentials gets 10. Professional gets 20
Clerk Pricing Breakdown
Clerk’s free tier at 10,000 MAU is the most generous in the auth space. That’s enough for most apps through their first year of growth. The Pro plan at $25/month includes those same 10,000 MAU and charges only $0.02 per additional MAU.
At 10,000 MAU: Clerk Pro costs $25/month. Auth0 Essentials costs $700/month. That’s a 28x price difference for the same user volume.
Clerk’s Strengths
- Pre-built UI components: Drop-in React/Next.js components for sign-in, sign-up, user profile, and organization management. Building auth UI from scratch on Auth0 takes days; Clerk takes minutes
- Multi-tenancy built-in: Organizations, roles, and invitations work out of the box. Auth0’s Organizations feature is Enterprise-only
- Modern framework integration: First-class support for Next.js, Remix, Astro, and Expo. Auth0 works with these but requires more configuration
- Webhook events: User created, updated, deleted events fire automatically. Useful for syncing auth state to your database
Cost at Scale
| Monthly Active Users | Auth0 Essentials | Clerk Pro | Savings with Clerk |
|---|---|---|---|
| 5,000 | $350 | $25 | 93% |
| 10,000 | $700 | $25 | 96% |
| 50,000 | $3,500 | $825 | 76% |
| 100,000 | $7,000 | $1,825 | 74% |
| 500,000 | $35,000 | $9,825 | 72% |
Clerk is 72–96% cheaper than Auth0 at every scale. At 100K MAU, choosing Clerk saves $62,100/year. That’s a senior engineer’s salary.
Feature Comparison
| Feature | Auth0 | Clerk |
|---|---|---|
| Social login | 50+ providers | 20+ providers |
| Passwordless (magic link) | Yes | Yes |
| Passkeys | Yes | Yes |
| MFA | Essentials+ (SMS, TOTP, push) | All plans (SMS, TOTP) |
| Pre-built UI | Universal Login (hosted page) | React components (embedded) |
| SAML SSO | Professional+ | Enterprise only |
| Organizations/Multi-tenancy | Enterprise only | All plans (free!) |
| Roles and permissions | Professional+ | All plans |
| Custom domains | Essentials+ | All plans |
| Webhooks | Yes (Actions) | Yes |
| M2M tokens | Yes (limited by plan) | Not applicable |
| HIPAA/SOC2 | Enterprise | Enterprise |
| SDK coverage | 30+ languages | JS/TS focused (React, Next, Remix, Expo) |
| Maturity | 10+ years | 3 years |
Where Auth0 Still Wins
- SDK breadth: 30+ SDKs covering every language and framework. If you’re building in Java, Python Django, PHP Laravel, or Go, Auth0’s SDK support is deeper
- Enterprise compliance: HIPAA, SOC2 Type II, FedRAMP — Auth0 has a longer compliance track record
- Social providers: 50+ social connections vs Clerk’s 20+. Matters if you need login via Apple, LinkedIn, Twitch, Discord, etc.
- Actions (serverless hooks): Run custom Node.js code during login flows — add custom claims, call external APIs, block suspicious logins
Where Clerk Wins
- Price: 72–96% cheaper. Not a minor difference
- Developer experience: Drop-in React components mean zero UI building. Auth screens look professional in minutes
- Organizations for free: Multi-tenant SaaS apps get organizations, roles, and invitations without paying for Enterprise
- Modern stack alignment: Built for Next.js, Remix, and Astro — the frameworks most new apps use in 2026
Other Alternatives
| Tool | Pricing | Best For |
|---|---|---|
| Supabase Auth | Free (50K MAU), then $25/mo + usage | Teams already using Supabase for database |
| Firebase Auth | Free (50K MAU), then $0.0055/MAU | Mobile apps and Google Cloud shops |
| Kinde | Free (10.5K MAU), then $0.035/MAU | B2B SaaS with feature flag needs |
| WorkOS | Free (1M MAU), then usage-based | Enterprise SSO-first products |
WorkOS deserves attention: 1 million free MAU for basic auth, with enterprise SSO add-ons priced per connection ($125/mo per SAML connection). If your app needs to sell to enterprises that require SSO, WorkOS’s per-connection model is cheaper than Auth0 or Clerk’s enterprise tiers.
Best for modern web apps: Clerk — 96% cheaper than Auth0, pre-built React components, and free organizations. The default choice for Next.js and React-based products in 2026.
Best for enterprise and legacy: Auth0 — deeper SDK coverage, longer compliance track record, and more social providers. Worth the premium if your stack isn’t JavaScript-centric or you need Actions for complex login flows.
Best free tier: WorkOS — 1M free MAU is unmatched. If basic auth is all you need, start here.
Best for Supabase users: Supabase Auth — 50K free MAU, and it’s already integrated with your database. No reason to add another service.
FAQ
What’s a MAU?
Monthly Active User — any unique user who logs in at least once during a billing month. A user who logs in once and one who logs in 100 times both count as 1 MAU.
Can I migrate from Auth0 to Clerk?
Yes. Clerk provides an Auth0 migration guide. User passwords can’t be exported from Auth0 (hashed), so migrated users need to reset their password on first login with Clerk. Social login connections transfer cleanly.
Is Clerk mature enough for production?
Clerk powers thousands of production apps including some well-known startups. It’s younger than Auth0 but stable and well-maintained. For most B2B and B2C SaaS apps, Clerk is production-ready.
Do I need a separate auth service at all?
If you’re using a framework with built-in auth (Rails, Django, Laravel), the built-in solution handles most needs. Third-party auth services make the most sense for: social login, passwordless, MFA, multi-tenancy, and cross-platform apps where building auth from scratch would take weeks.
