There have been numerous queries about "bulletproof nextjs saas", "nextjs saas kit bulletproof", "best bulletproof next.js template", "saas starter kit by bulletproof next js github", etc.
None of those refers to any officially released product. Those phrases were chosen to describe ixartz SaaS Boilerplate, which is a free, open-source Next.js SaaS starter kit created by Remi Weng (ixartz) and based on the Bulletproof React architecture guide adjusted for Next.js and SaaS functionality built on top of it. In the following review, we will explain what the ixartz boilerplate is doing well, what can be improved and how it compares to Kostra – our paid, production-ready solution.
Disclosure: This review is written by the Kostra team. We analysed the ixartz boilerplate based on its publicly available GitHub repository and documentation.
What Is the Bulletproof Next.js SaaS Boilerplate?
The name comes from the "Bulletproof React" architecture guide that suggests certain practices of building React apps: a feature-based folder structure, separation of concerns and a set of conventions to keep a codebase clean and easy to maintain. The ixartz boilerplate is an implementation of these concepts for Next.js with all SaaS-related functionality built on top.
Whatever you decide to call it, Next.js SaaS boilerplate, a SaaS starter kit, boilerplate code, it is the same repository. It is completely free and open source (MIT license).
As of 2026, it is one of the most starred free Next.js SaaS starters on GitHub with thousands of stars and frequent commits.
Despite the existence of the paid Pro version (~ $99 for life) with landing page templates and extra components, the boilerplate itself remains absolutely free.
GitHub: github.com/ixartz/SaaS-Boilerplate
Note before publishing: make sure you check the current number of stars and verify that it uses the Next.js 16 version when this review is published. Both numbers change, and it is an easy way to spot a mistake in the review for the ixartz community.
Full Feature Breakdown
Authentication (Clerk)
The first controversy of this boilerplate – authentication system. The boilerplate uses Clerk as an authentication provider.
What you get with Clerk:
Email/password, social OAuth (Google, GitHub, and 15+ providers)
Magic links
Passkeys
Multi-Factor Authentication (MFA)
User impersonation (for debugging user-specific issues)
A pre-built user management dashboard
The trade-off: since Clerk is a hosted service, you won't store your user data in your database – instead, it will go to Clerk's server. Clerk has a generous free tier, but once you start using the service over that tier, you will be charged depending on the number of monthly active users, and it may be quite expensive in case your product grows into tens of thousands of users. When you have specific data residency requirements, Clerk makes you depend on a third-party service.
This isn't a reason to skip the boilerplate – this is a reason to read the Clerk pricing page.
Multi-Tenancy and Organizations
True multi-tenancy and data scoping by organisations. User belongs to an organisation, and all data objects belong to organisations, not individual users. There are three roles for an organisation: owner, admin and member. Users can switch between the organisations they belong to.
This is what separates a real multi-tenant SaaS solution from any starter kit that has the "team support" on top of the standard user model. This is a great achievement for a free boilerplate.
What does it use: the organisation management capabilities of Clerk, which are integrated with the database. Data of organisation flow from Clerk to your database, which means that tenant data is stored partially in the Clerk infrastructure and partially in your database.
Database and ORM
Drizzle ORM is used with the support for PostgreSQL, SQLite and MySQL. Drizzle is currently a preferred ORM for Next.js projects due to its lightweight and SQL-like query syntax.
The migration process is standard: each change in a schema results in the creation of migration files that can be executed with the pnpm migrate command.
Type-safe migrations.
Stripe Billing
Integrated Stripe billing with the subscription and a pricing page. A webhook handler for the main subscription events. Based on the community feedback and our analysis, this is the best coverage compared to other free alternatives.
Should be checked before release: does it handle the customer.subscription.updated and invoice.payment_failed events? Check the switch case in src/app/api/webhooks/stripe/route.ts.
Internationalisation (i18n)
A complete i18n with Crowdin for translation support out-of-the-box. Supports multiple locales.
Our honest recommendation: most developers who are developing their first SaaS products don't need i18n from day one. This is an additional complexity for your codebase that should be removed if you don't need multiple locales at the moment.
Testing
Vitest for unit tests, Playwright for end-to-end testing, pre-configured CI/CD pipeline in GitHub Actions.
This is one of the strongest differentiators of the ixartz boilerplate against other free options. Most free boilerplates come with zero tests out of the box, while the ixartz one has meaningful testing coverage and a CI/CD pipeline configured.
Error Monitoring and Logging
Sentry integration included. Structured logging with LogTape. It is a professional-level error monitoring and logging, not plain console.logs.
Security
Integration with Arcjet for bots detection, rate limiting and attacks protection on the middleware level. This is a relatively new addition, and this feature puts the ixartz boilerplate ahead of its alternatives (whether paid or free).
Developer Tooling
ESLint, Prettier, Lefthook (instead of Husky), Commitlint, Storybook for components and CodeRabbit for AI code reviews.
Tech Stack Summary
What the Ixartz Boilerplate Does Well
Active, consistent maintenance. This is by far the best thing the boilerplate has over other free alternatives. There's someone proactive in terms of following Next.js releases and upgrading the boilerplate accordingly, updating legacy packages (e.g., Husky replaced with Lefthook, Jest with Vitest, Pino with LogTape), and shipping the updates whenever there are ecosystem changes. Proactive maintenance is rarely seen in free open source projects. This one has it.
Genuine multi-tenancy. Real organisational support with proper data scoping, not just tagging users. Roles management at the organisation level. Changing organisations and working with organisations. For a free boilerplate, this multi-tenancy implementation is production-grade.
Production tooling included. Sentry, Arcjet, structured logging, Vitest, Playwright, CI/CD. You get the production tooling configured without setting them up. Most of the free starters have none of these, or just a few of them.
Architectural patterns. The Bulletproof React patterns enforced here: feature-based folder structure, clear separation of client and server code, consistent conventions throughout. A team onboarding to this codebase can orient itself quickly because the patterns are predictable.
Where the Ixartz Boilerplate Falls Short
No email system. No email transactions are set up in the boilerplate. There's no Resend, no AWS SES, no email templates. The setup of these things has to be done manually. Plan for a day for Resend and templates configuration.
No file storage. No AWS S3, Cloudflare R2, or any other file storage solution is integrated. This is not an issue for a product that doesn't require file handling at all.
Clerk dependency and cost at scale. Clerk is awesome, but it adds to the cost of your app as you become dependent on it and have per-user pricing. Developers requiring self-hosted authentication, data residency control, or a different authorisation provider need to replace the whole auth layer, which is a non-trivial change.
No Docker support. The boilerplate is meant to be deployed via Vercel only. No Dockerfile, no Docker Compose configuration. For the teams that need containerization, self-hosting, or AWS ECS/Google Cloud Run deployment, Docker needs to be added by hand.
Feature accumulation requires stripping. The boilerplate comes packed with i18n, Storybook, Crowdin integration, and some other features that many products don't need at the very beginning. Run npm run build after stripping the unnecessary features to check broken imports.
Who the Ixartz SaaS Boilerplate Is Best For
Individual developers or small teams that build multi-tenant SaaS products and need the most feature-rich free basis they can get. A combination of active maintenance, multi-tenancy, production tooling, and the zero price tag makes this boilerplate unique.
Developers who are looking to learn about SaaS architecture through the example of how multi-tenancy, auth, and billing look in the codebase.
MVPs that need to go fast and, for now, don't have the concerns regarding the cost of Clerk's free tier.
Not recommended for teams that need Docker deployment, AWS S3/R2 file storage, AWS SES emails, or self-hosted auth out of the box. Not for products where Clerk's per-MAU cost makes a difference.
How It Compares to Kostra
Given that this review comes from the Kostra development team, here’s an unbiased comparison. (If you are comparing Kostra to the T3 Stack rather than to ixartz, read our comparison of T3 Stack vs Kostra comparison.)
Points in common between the ixartz SaaS Boilerplate and Kostra include: Multi-tenancy
RBAC
Stripe billing
TypeScript
Shadcn UI
Choose ixartz if you seek the most robust free option, find acceptable Clerk pricing terms, and have no need for Docker, file storage, or ready-made email setup.
Choose Kostra if you require the users' data in your own database, Docker deployment, AWS S3/R2 file storage, or AWS SES email. In addition, Kostra's layered architecture (Atomic Design + repository pattern + service layer) would be more suitable for a bigger team where the benefits of the service layer's separation of concerns will be noticeable.
The Honest Verdict
ixartz SaaS Boilerplate definitely deserves the title of the best free Next.js SaaS starter for 2026. Its active maintenance, true multi-tenancy, production-ready tools, and Bulletproof architectural patterns speak of real value. For a free product, that's quite impressive.
However, the drawbacks are also serious: no email integration, no file storage, no Docker support, and Clerk vendor lock-in. Not every project will suffer from these restrictions. Some will handle them without problems; some might see it as an extra reason to go paid.
If your needs align with what it offers out of the box: take it. Free, actively maintained, and will help you create a multi-tenant SaaS product much faster than anything else available in the free tier.
Need file storage, custom email setup, Docker setup, or custom authentication? Count a couple of days to integrate all these into your app and only then consider it as a fully-fledged starter.
Still wondering whether this is better than other contenders for the position of the best Next.js SaaS kit? Check our Top 10 Best Next.js Boilerplates review for more details.
FAQs
What is the Bulletproof Next.js SaaS starter kit?
"Bulletproof Next.js SaaS starter kit" is the community name of the ixartz SaaS Boilerplate (github.com/ixartz/SaaS-Boilerplate), a free open-source Next.js SaaS starter made by developer Remi Weng. "Bulletproof" refers to the use of the opinionated architectural patterns found in the Bulletproof React guide, adapted for Next.js. There is no official product called "Bulletproof Next.js."
Is the ixartz SaaS boilerplate really free?
Yes. The core boilerplate is free and MIT licensed. There is a paid Pro tier (~$99 lifetime) that adds some extra landing page templates and priority support. All of the features that we're discussing in this review – multi-tenancy, Clerk auth, Stripe, Drizzle ORM, testing suite, CI/CD, Sentry, Arcjet – are included in the free version.
What is Clerk and does the ixartz boilerplate require it?
Clerk is a hosted authentication service. The ixartz SaaS Boilerplate was designed with Clerk in mind. Switching to a different auth provider would require a large refactoring of the auth layer. If you know you want to go with self-hosted auth and store user data in your own database, either accept the refactoring or find a different boilerplate to start with.
Does the Bulletproof Next.js boilerplate include email?
No. Email integration is not included in the ixartz boilerplate. You will need to add it yourself (Resend, AWS SES, etc.).
Does the ixartz boilerplate support Docker?
No. The ixartz SaaS Boilerplate is designed for deployment to Vercel. There is no Dockerfile and no Docker Compose config provided.
How does the ixartz SaaS boilerplate compare to Kostra?
They are similar in the sense of both being actively maintained Next.js SaaS starters with multi-tenancy and Stripe billing. The main differences are as follows: ixartz boilerplate is free, Clerk-based auth, Drizzle ORM, and does not come with email/file storage support out-of-the-box. Kostra boilerplate costs $150 one-time, custom auth with JWT, user data in your own database, Prisma ORM, comes with preconfigured integration tests, Resend/AWS SES email integration, AWS S3/Cloudflare R2 file storage support, Docker deployment support. Choose ixartz if you want to use the free tier and Bulletproof architecture. Choose Kostra if you need infrastructure flexibility and layered production architecture.
Is the ixartz SaaS boilerplate production-ready?
Yes, with the caveat that the "production-ready" status largely depends on what kind of requirements your product has. It includes Sentry monitoring, Arcjet security, and a full test suite. The Stripe integration works well; multi-tenancy is real. For most SaaS MVPs, the ixartz boilerplate is production-ready out-of-the-box. But if you need email, file storage, Docker deployment or self-hosted auth – you will be adding all of these anyway before going to production.
What is the best SaaS template for Next.js?
There's no single best Next.js SaaS template; it depends on what you need pre-built. ixartz is the strongest free option if you're fine with Clerk's auth model. Kostra is the strongest paid option if you need self-hosted auth, file storage, and Docker out of the box. Our Top 10 Best Next.js Boilerplates roundup covers more options.
How do I build a SaaS with a Next.js template?
Build your product on top of a starter template that has auth, billing, and a database layer already built. With ixartz, Clerk takes care of the auth part, and Stripe takes care of the billing – all wired up. In the case of Kostra, everything is wired up out-of-the-box, so you can start implementing product features from day one.
Are there free SaaS templates for Next.js?
Yes. As of mid-2026, the most complete free SaaS template is ixartz SaaS Boilerplate with multi-tenancy, Stripe billing and a full test suite included. The trade-off here is no email/file storage/Docker deployment out-of-the-box.
Which Next.js SaaS template is best for beginners?
ixartz is a decent option for those who want to understand the inner workings of the SaaS auth/billing/database layer, and it's free. If you prefer a product that is already production-ready without having to assemble the pieces yourself, then Kostra makes that learning curve much smaller (with the trade-off of a one-time payment).
What are the best alternatives to the Bulletproof Next.js SaaS starter kit?
Free alternatives:
nextjs/saas-starter (official Vercel minimal starter),
boxyhq/saas-starter-kit (enterprise compliance focus),
create-t3-app (type-safe stack with no SaaS features built in; see our full T3 Stack vs Kostra comparison if you're considering this path).
Paid alternatives:
Kostra ($150, infrastructure flexibility, Docker)
Supastarter (advanced multi-tenancy, Lemon Squeezy support)
MakerKit (Supabase ecosystem, plugin system)
ShipFast (speed-focused for solo founders)
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