Authentication Libraries Comparison: Better Auth, NextAuth.js, and Clerk
This report provides a detailed comparison of three authentication libraries for modern web development, focusing on Better Auth, NextAuth.js (Auth.js), and Clerk. These libraries are widely used in Next.js applications, each offering unique features, trade-offs, and use cases. The comparison evaluates their functionality, ease of use, customization, security, performance, pricing, and community support to help developers choose the right solution for their projects.
1. Overview of Each Library
Better Auth
- Website: https://www.better-auth.com/
- Description: Better Auth is a TypeScript-first, open-source authentication framework designed to provide a comprehensive, extensible, and developer-friendly solution. It emphasizes control, flexibility, and integration with modern frameworks like Next.js, React, Vue, and Svelte.
- Key Features: Email/password authentication, OAuth support, multi-factor authentication (MFA), multi-tenancy, plugin ecosystem, and full control over user data in your database.
NextAuth.js (Auth.js)
- Website: https://authjs.dev/
- Description: NextAuth.js, now transitioning to Auth.js, is an open-source authentication library tailored for Next.js applications. It provides a flexible, serverless-first approach with support for multiple authentication providers and database integrations.
- Key Features: OAuth, email/password, magic links, JWT or database-backed sessions, and customizable authentication flows via callbacks.
Clerk
- Website: https://clerk.com/
- Description: Clerk is a managed authentication and user management service designed for simplicity and rapid integration with Next.js and other frameworks. It offers pre-built UI components and a developer-friendly API, focusing on ease of use and security.
- Key Features: Pre-built UI components, MFA, social logins, session management, and organization management with a focus on developer experience.
2. Detailed Comparison
The following sections compare the libraries across key dimensions: setup and integration, features, customization, security, performance and scalability, pricing, documentation and community, and use cases.
2.1 Setup and Integration
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| Ease of Setup | Moderate. Requires configuration of server-side auth instance and database schema. Provides auto-generated Drizzle schemas for TypeScript users. | Moderate. Simple for basic setups with OAuth providers, but complex for custom flows or database integrations. Requires adapter setup for ORMs like Prisma. | Very easy. Plug-and-play with pre-built components and minimal configuration. Wrap app with <ClerkProvider> and use components like <SignIn />. |
| Framework Support | Broad support: Next.js, React, Vue, Svelte, Astro, Solid, Nuxt, Hono, and more. | Primarily Next.js, with support for other frameworks via Auth.js migration. | Strong Next.js integration; also supports React, Remix, and Expo. |
| Database Integration | Full control over database schema. Stores user data in your database, supporting Drizzle, Prisma, and others. | Flexible with adapters for Prisma, Supabase, MongoDB, etc. Can be serverless with JWT. | Managed service; user data stored on Clerk’s servers. Webhooks for syncing to your database. |
| Learning Curve | Moderate. Requires understanding of TypeScript and server-side setup. Plugin system simplifies advanced features. | Steep for custom flows due to complex callbacks and adapter setup. Simpler for basic OAuth. | Low. Pre-built components and clear dashboard reduce learning curve. |
Analysis:
- Better Auth shines for developers who want control over their auth flow and database schema. Its TypeScript-first approach and plugin system make it extensible, but setup requires more effort than Clerk.
- NextAuth.js is flexible but can be cumbersome for complex setups due to adapter and callback configurations. It’s ideal for developers comfortable with Next.js and willing to tweak configurations.
- Clerk is the easiest to set up, especially for rapid prototyping or teams prioritizing speed. However, its managed service model limits control over data storage.
2.2 Features
| Feature | Better Auth | NextAuth.js | Clerk |
|---|
| Authentication Methods | Email/password, OAuth (Google, GitHub, Discord, etc.), magic links. | OAuth, email/password, magic links, credentials. | Email/password, OAuth, magic links, passkeys, WebAuthn. |
| MFA | Supported via plugins (e.g., two-factor authentication). | Supported but requires custom implementation. | Built-in MFA (SMS, email, TOTP). |
| Session Management | Robust session handling with client/server-side APIs. | JWT or database-backed sessions. Flexible but complex. | Advanced session management with multi-session support. |
| Multi-Tenancy | Built-in support for organizations, teams, and invitations. | Limited; requires custom implementation. | Strong organization management with role-based access. |
| Social Logins | Multiple providers via configuration. | Extensive provider support (Google, GitHub, Apple, etc.). | Seamless social login integration with pre-built UI. |
| UI Components | No pre-built UI; requires custom implementation. | No pre-built UI; fully custom. | Pre-built, customizable components (<SignIn />, <UserButton />). |
| Plugin Ecosystem | Extensive plugin system for MFA, rate limiting, admin tools. | Limited; relies on custom callbacks. | Limited; relies on webhooks and integrations. |
Analysis:
- Better Auth offers a comprehensive feature set, especially for TypeScript developers. Its plugin system allows easy addition of advanced features like MFA or rate limiting, making it highly extensible.
- NextAuth.js is feature-rich but requires more manual configuration for advanced features like MFA or multi-tenancy, which can increase development time.
- Clerk excels in providing a polished, out-of-the-box experience with pre-built UI components and built-in MFA. It’s ideal for teams needing a complete user management solution without building custom UI.
2.3 Customization
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| UI Customization | Fully custom; no pre-built UI, giving complete control. | Fully custom; no pre-built UI, requires building from scratch. | Customizable via appearance prop and CSS, but limited to Clerk’s components. |
| Auth Flow Customization | High flexibility via plugins and server-side configuration. | High flexibility via callbacks, but complex to implement. | Moderate; webhooks and APIs allow some customization. |
| Data Model Control | Full control over database schema and user data. | Flexible with adapters, but schema depends on adapter choice. | Limited; user data managed by Clerk, synced via webhooks. |
Analysis:
- Better Auth and NextAuth.js offer maximum customization, as developers build their own UI and auth flows. Better Auth’s plugin system simplifies extending functionality, while NextAuth.js relies on callbacks, which can be error-prone.
- Clerk sacrifices some customization for simplicity. Its pre-built components are customizable but less flexible than fully custom solutions. Webhooks provide some control, but data resides on Clerk’s servers.
2.4 Security
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| Security Features | MFA, rate limiting, CSRF/XSS protection via plugins. | CSRF protection, JWT security. MFA requires custom setup. | MFA, bot detection, brute-force protection, CSRF/XSS protection. |
| Compliance | Depends on implementation; no built-in certifications. | Depends on implementation; no built-in certifications. | SOC 2 Type II, CCPA compliant. |
| Data Privacy | User data stored in your database, full control. | User data stored in your database or JWT, full control. | User data on Clerk’s servers, synced via webhooks. |
| Known Issues | Young project; less battle-tested in production. | Reports of random logouts and session issues. | Polished but relies on third-party hosting. |
Analysis:
- Better Auth provides robust security features through plugins, but its relative newness means it’s less battle-tested. Developers must ensure proper configuration for compliance.
- NextAuth.js has faced criticism for session management issues (e.g., random logouts) and lacks clear documentation for critical settings like session lifetime.
- Clerk offers enterprise-grade security with compliance certifications and built-in protections, making it ideal for projects with strict security requirements. However, reliance on Clerk’s servers raises data privacy concerns for some.
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| Performance | Depends on database and server setup; optimized for TypeScript. | Serverless-friendly with JWT, but database-backed sessions can be slower. | Managed service; optimized for performance with global CDN. |
| Scalability | Scales with your infrastructure; requires proper DevOps. | Scales with your infrastructure; adapters impact performance. | Highly scalable; managed infrastructure handles load. |
| Serverless Support | Compatible with serverless via frameworks like Next.js. | Strong serverless support with JWT sessions. | Fully serverless; no infrastructure management needed. |
Analysis:
- Better Auth and NextAuth.js rely on your infrastructure, so performance and scalability depend on your database and server setup. Both are serverless-compatible but require careful optimization.
- Clerk benefits from a managed infrastructure with global CDN, ensuring high performance and scalability without DevOps overhead. This makes it ideal for startups and SaaS products.
2.6 Pricing
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| Cost | Free (open-source). Hosting and database costs apply. | Free (open-source). Hosting and database costs apply. | Free tier (up to 10,000 monthly active users). Business plan: $550/month for 10,000 users. |
| Hidden Costs | Dev time for setup, maintenance, and custom UI. | Dev time for setup, custom flows, and maintenance. | Webhook setup for data syncing; potential overage fees. |
Analysis:
- Better Auth and NextAuth.js are free, but development and maintenance time can be significant, especially for complex setups.
- Clerk’s free tier is generous, but costs scale quickly for high user volumes. For 10,000 active users, $550/month is reasonable if it saves development time, but it’s a recurring expense.
2.7 Documentation and Community
| Aspect | Better Auth | NextAuth.js | Clerk |
|---|
| Documentation | Comprehensive, TypeScript-focused. Still evolving due to young project. | Extensive but often criticized for being unclear or outdated. | Polished, clear, with tutorials and dashboard. |
| Community Support | Growing community; active on GitHub and Discord. | Large community; active on GitHub, Discord, and forums. | Smaller but responsive community; strong official support. |
| Maintenance | Actively maintained; frequent updates. | Actively maintained, but v5 beta has been slow to stabilize. | Managed service; regular updates with minimal developer effort. |
Analysis:
- Better Auth has solid documentation for a young project, with a growing community. Its TypeScript focus makes it appealing to modern developers.
- NextAuth.js benefits from a large community but suffers from documentation issues and slow progress on v5, causing frustration.
- Clerk offers the best documentation and official support, with a user-friendly dashboard and tutorials. Its community is smaller but sufficient for most needs.
2.8 Use Cases
| Use Case | Better Auth | NextAuth.js | Clerk |
|---|
| Rapid Prototyping | Moderate; requires custom UI and setup. | Moderate; quick for OAuth but slower for custom flows. | Best; pre-built components and managed service. |
| Open-Source Projects | Good; free and flexible for contributors. | Best; widely used, no external service dependency. | Moderate; free tier helps, but managed service adds complexity. |
| Enterprise Apps | Good; extensible but requires compliance setup. | Moderate; lacks built-in compliance features. | Best; SOC 2 compliance and enterprise features. |
| Custom Auth Flows | Best; plugin system and full control. | Good; flexible but complex callbacks. | Moderate; limited by managed service model. |
| SaaS Products | Good; supports multi-tenancy and scalability. | Moderate; requires custom multi-tenancy. | Best; built for SaaS with organization management. |
Analysis:
- Better Auth is ideal for developers needing custom auth flows and TypeScript integration, especially for SaaS or multi-tenant apps.
- NextAuth.js suits open-source projects and developers comfortable with Next.js, but it struggles with complex enterprise needs.
- Clerk is perfect for rapid development, SaaS products, and enterprise apps requiring compliance and polished user experiences.
3. Pros and Cons
Better Auth
Pros:
- TypeScript-first with auto-generated schemas.
- Extensive plugin system for MFA, rate limiting, etc.
- Full control over user data and database.
- Broad framework support.
- Free and open-source.
Cons:
- Young project; less battle-tested.
- No pre-built UI, increasing dev time.
- Moderate learning curve for server-side setup.
NextAuth.js
Pros:
- Free and open-source.
- Flexible with multiple providers and database adapters.
- Large community and ecosystem.
- Serverless-friendly with JWT.
Cons:
- Complex for custom flows and advanced features.
- Documentation issues and slow v5 progress.
- Session management issues (e.g., random logouts).
- Steep learning curve for non-standard use cases.
Clerk
Pros:
- Easiest setup with pre-built, customizable UI.
- Enterprise-grade security and compliance (SOC 2, CCPA).
- Advanced features like MFA and organization management.
- Managed service reduces DevOps overhead.
- Polished documentation and dashboard.
Cons:
- Recurring costs for high user volumes.
- Limited control over user data (managed service).
- Less flexible for highly custom auth flows.
- Smaller community compared to NextAuth.js.
4. Recommendations
Based on the comparison, here are tailored recommendations:
-
Choose Better Auth if:
- You’re building a TypeScript-heavy project and want full control over your auth flow and database.
- You need advanced features like multi-tenancy or MFA with minimal configuration via plugins.
- You prefer an open-source solution and are comfortable building custom UI.
- Best for: Custom SaaS apps, multi-tenant platforms, and developers prioritizing flexibility.
-
Choose NextAuth.js if:
- You’re working on an open-source Next.js project and need a free, flexible solution.
- You’re comfortable with Next.js and willing to invest time in custom configurations.
- You don’t need enterprise-grade compliance or pre-built UI.
- Best for: Open-source projects, small to medium apps, and serverless setups.
-
Choose Clerk if:
- You need a fast, polished authentication solution with minimal setup.
- Your project requires enterprise-grade security, compliance, or advanced user management.
- You’re building a SaaS product or prototyping rapidly and can afford the pricing.
- Best for: SaaS startups, enterprise apps, and teams prioritizing speed and user experience.
5. Conclusion
Each library serves distinct needs in the authentication landscape:
- Better Auth offers a modern, TypeScript-first approach with unmatched flexibility and a promising plugin ecosystem, ideal for developers who want control and extensibility.
- NextAuth.js remains a staple for Next.js developers, offering flexibility and a large community, but it struggles with complexity and documentation issues.
- Clerk provides a premium, managed experience with enterprise-grade features and ease of use, perfect for teams prioritizing speed and compliance.
Ultimately, the choice depends on your project’s requirements, budget, and team expertise. For rapid development and enterprise needs, Clerk is the go-to. For custom, TypeScript-driven projects, Better Auth is a strong contender. For open-source or highly customized Next.js apps, NextAuth.js is still viable despite its challenges.
6. References