How to Launch a SaaS for $0: Complete Free Tools Stack 2026

Here's a claim that would have been absurd five years ago: you can build, launch, and scale a SaaS product in 2026 without spending a single dollar on infrastructure. Not a prototype. Not a toy. A real product with authentication, a database, payments, monitoring, and a custom domain.

The free tiers have gotten that good.

I've been tracking every free tool and startup program available, and the combined value is staggering. Here's the complete $0 SaaS stack.

The $0 SaaS Stack Is Real in 2026

Let's be upfront: "free" doesn't mean "free forever at any scale." These free tiers are designed for early-stage products — exactly the stage where you shouldn't be spending money on infrastructure. You should be spending your limited time and energy on finding product-market fit, not optimizing AWS bills.

The strategy: use free tiers to build and launch. Once you have paying customers, use that revenue to upgrade to paid plans. If you never get paying customers, you spent $0 learning what doesn't work.

Here's the stack.

Frontend & Hosting

Primary: Next.js + Vercel

Vercel's Pro plan is free for students and open source projects. For a SaaS landing page, dashboard, and API routes, it's hard to beat:

Automatic deployments from Git
Preview URLs for every pull request
Edge functions for API routes
Image optimization built in
Analytics included

Alternative: Railway

If you need persistent servers (WebSockets, background jobs, cron tasks), Railway is better suited. The $5/month free credit covers a small app with a database.

For a detailed comparison, see Vercel vs Railway.

Database & Backend

Primary: Supabase

Supabase gives you PostgreSQL + auth + storage + realtime in one platform. The free tier is genuinely generous:

500 MB PostgreSQL database
50,000 monthly active users (auth)
1 GB file storage
Realtime subscriptions
Edge functions
Auto-generated REST and GraphQL APIs

For most early-stage SaaS products, this covers everything. You don't need a separate auth service, file storage service, or API layer — Supabase includes it all.

Alternative: MongoDB Atlas

If you prefer NoSQL or your data model is document-oriented, MongoDB Atlas offers a free M0 cluster (512 MB) plus $200 in student credits.

For a deeper database comparison, see Best Free Databases for Side Projects.

Authentication

Authentication is the first thing every SaaS needs and the first thing every founder wants to avoid building from scratch. Good news: you don't have to.

Option 1: Supabase Auth (included free)

If you're using Supabase for your database, auth is already included. Email/password, OAuth (Google, GitHub, Discord), magic links, phone OTP — all built in. For most projects, this is the obvious choice.

Option 2: Clerk (free up to 10,000 MAU)

Clerk is a modern auth service with beautiful pre-built components. Drop in a <SignIn /> component and you have a complete auth flow with social login, MFA, and user management. Free for up to 10,000 monthly active users.

Option 3: NextAuth.js / Auth.js (open source)

If you want full control, Auth.js is the open source standard for Next.js authentication. It supports dozens of providers, database adapters, and JWT/session strategies. No limits, no vendor lock-in.

Payments

You don't pay for payment processing until you make money — both options below charge per transaction, not monthly.

Option 1: Stripe

Stripe is the developer's payment platform. 2.9% + 30¢ per transaction, no monthly fee. The API is beautifully designed, documentation is industry-leading, and the ecosystem (Stripe Checkout, Billing, Customer Portal) handles subscriptions effortlessly.

If you're incorporating a company, Stripe Atlas handles Delaware C-Corp formation and automatically connects you to startup programs for AWS, Notion, and other tools.

Option 2: LemonSqueezy

LemonSqueezy is a "merchant of record" — they handle sales tax, VAT, and compliance for you. The fee is higher (5% + 50¢), but for solo founders selling digital products, the time saved on tax compliance is worth it.

For a detailed comparison, see Stripe vs LemonSqueezy.

Monitoring & Analytics

You need to know when things break and how users behave. Both are free.

Error tracking: Sentry

Sentry catches errors in production and gives you stack traces, breadcrumbs, and user context. The free tier includes 5,000 events/month. For open source projects, Sentry provides unlimited events.

Analytics: Vercel Analytics

Included with Vercel Pro (free for students). Track page views, web vitals, and user behavior without third-party scripts slowing down your site.

Uptime: Better Uptime

Better Uptime monitors your endpoints and alerts you when something goes down. Free tier includes 10 monitors with 3-minute check intervals.

For a comprehensive guide, see Best Free Monitoring for Startups.

Domain & Email

Domain: Cloudflare

Register your domain through Cloudflare Registrar (at-cost pricing, no markup) and get free DNS, CDN, DDoS protection, and SSL. Their startup program provides additional credits and features.

Transactional email: Resend

Resend offers 3,000 emails/month free. For transactional emails (password resets, welcome emails, receipts), this covers most early-stage products. The API is clean and it integrates with React Email for beautiful templates.

The Complete Stack Diagram

| Layer | Tool | Free Tier | Monthly Cost | |-------|------|-----------|-------------| | Frontend | Next.js + Vercel | Pro plan (students/OSS) | $0 | | Database | Supabase | 500 MB + auth + storage | $0 | | Auth | Supabase Auth or Clerk | Included / 10K MAU | $0 | | Payments | Stripe | Per-transaction only | $0* | | Error tracking | Sentry | 5K events/month | $0 | | Analytics | Vercel Analytics | Included | $0 | | DNS + CDN | Cloudflare | Free plan | $0 | | Email | Resend | 3K emails/month | $0 | | Uptime | Better Uptime | 10 monitors | $0 | | Total | | | $0/month |

*Stripe charges per transaction — you only pay when you make money.

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