Open-Source SaaS Boilerplates in 2026: Free, Production-Ready Options Compared
A SaaS boilerplate ships the undifferentiated parts of a subscription product — auth, billing, teams, email — already working. The strongest free options in 2026 are open source: Vercel's Next.js SaaS Starter, BoxyHQ's enterprise kit, Wasp's Open SaaS, and per-framework equivalents for Django, Laravel and SvelteKit.
What a SaaS boilerplate should already contain
Every subscription product rebuilds the same six subsystems before writing a line of differentiated code. A boilerplate earns its place by shipping all of them wired together:
- Authentication — email, social login, and for B2B products SSO/SAML, because enterprise buyers ask for it in the first call.
- Billing — Stripe (or Paddle) with real webhook handling, plan changes and a customer portal, not just a checkout link.
- Multi-tenancy — a teams or workspaces model with roles and invitations; retrofitting tenancy onto a single-user schema is the most expensive migration in SaaS.
- Transactional email — verification, receipts, invitations, with a provider integration and templates.
- An admin surface — enough to look up a customer and fix their state without opening a database console.
- Deploy configuration — a deploy button or docker-compose that proves the whole assembly actually runs outside the author's laptop.
Free and open-source SaaS boilerplates compared
| Boilerplate | Stack | Auth | Billing | Multi-tenancy | Licence |
|---|---|---|---|---|---|
| Next.js SaaS Starter (Vercel) | Next.js, Postgres, shadcn/ui | Email/password, JWT sessions | Stripe + customer portal | Teams with roles | MIT |
| SaaS Starter Kit (BoxyHQ) | Next.js, Prisma, Auth.js | Email, social, SAML SSO | Stripe | Teams, invitations, audit logs | Apache-2.0 |
| Open SaaS (Wasp) | React, Node, Prisma (Wasp) | Email, social | Stripe | Per-user, demo AI app included | MIT |
| Nextacular | Next.js, Prisma, Tailwind | Auth.js (magic links, social) | Stripe | Workspaces + custom domains | MIT |
| CMSaasStarter | SvelteKit, Supabase | Supabase Auth | Stripe | Per-user | MIT |
| Wave (DevDojo) | Laravel, Filament | Built-in | Subscription billing | Per-user, roles | Open source |
| cookiecutter-django | Django, Docker | django-allauth | Add dj-stripe yourself | Build your own | BSD |
| full-stack-fastapi-template | FastAPI, React, Postgres, Docker | JWT | None included | Build your own | MIT |
Pick by the hardest feature you need
The comparison collapses once you name the feature that would be most expensive to add by hand. Enterprise SSO effectively decides for BoxyHQ — SAML is weeks of work nobody enjoys. Customer-facing custom domains point at Nextacular. A Supabase backend points at CMSaasStarter on SvelteKit, or the equivalent Supabase starters in the Next.js world. A Python team gets more from FastAPI's official template plus a billing library than from fighting a JavaScript stack.
The same logic applies to what you can safely leave out: a boilerplate with multi-tenancy you do not need is schema complexity you will carry forever. Single-user products can start smaller and stay honest.
Paid vs open source: what $200–$300 actually buys
Paid kits — ShipFast, Makerkit, SaaS Pegasus, supastarter — sell polish, documentation, support and continuous updates. They are not selling anything you cannot assemble from the open-source table above; they are selling the week you would spend assembling it. That trade can be rational for a funded project and is rarely necessary for a first product.
Two cautions apply. Paid kit licences are per-developer and prohibit redistribution, which matters if you plan to open-source any part of your product. And a paid kit is still someone else's architecture: evaluate its maintenance and community exactly as the checklist for open-source boilerplates demands, because the failure mode — abandoned kit, locked-in schema — is identical.
AI SaaS boilerplates
An AI SaaS starter adds three subsystems to the standard six: LLM provider integration with key management, usage metering (credits or token budgets, because per-seat pricing does not survive inference costs), and often a vector store for retrieval. Wasp's Open SaaS ships a working AI demo app; most other kits leave the AI layer to you.
This is where a catalog of analysed components pays off: the RAG, inference and agent-framework projects in the RepoLoot catalog are exactly the layer an AI SaaS bolts onto its boilerplate — each analysed for difficulty, licence and what you can realistically build on it.
Frequently asked questions
- What is the best free SaaS boilerplate?
- For most teams in 2026: Vercel's Next.js SaaS Starter for a lean start, BoxyHQ's SaaS Starter Kit when you need enterprise SSO and audit logs, Open SaaS by Wasp for an AI-flavoured product, and CMSaasStarter for SvelteKit with Supabase. All are MIT or Apache-2.0 licensed.
- Do SaaS boilerplates include Stripe?
- The mature ones do — including webhook handling, plan changes and the customer portal, which is the part that actually takes time. Treat a boilerplate whose 'Stripe integration' is a checkout link as not having billing at all.
- What is multi-tenancy in a SaaS boilerplate?
- The data model that lets one deployment serve many isolated customers — usually workspaces or teams with roles and invitations. It is the hardest thing to retrofit later, so choose a boilerplate with tenancy if B2B customers are the plan, and skip it if they are not.
- Should I use a paid or an open-source SaaS boilerplate?
- Open source first. Paid kits ($200–$300) buy polish, support and updates rather than unique capability, and their per-developer licences prohibit redistribution. The open-source options above cover auth, billing and teams under MIT or Apache-2.0.