Build a complete SaaS product on free tiers. 12 infrastructure categories — hosting, database, auth, payments, email, storage, monitoring, CI/CD, analytics. Exact limits, growth costs at 1K/10K/100K users.

The Complete Free SaaS Starter Stack for 2026

You can build and launch a complete SaaS product without spending a dollar on infrastructure. This guide gives you the opinionated "just tell me what to use" answer — the best free tier for each layer of a SaaS stack, with exact limits pulled from our index of 1,547+ verified developer tools.

Every recommendation includes alternatives, "when you'll outgrow it" guidance, "why not X" callouts for popular-but-not-recommended options, and stability notes based on our tracking of 554 real pricing changes. The limits on this page were read from vendor pricing pages between 2026-07-24 and 2026-09-04.

TL;DR — The $0/Month SaaS Stack

If you're building a SaaS today, use these. Each one is the best free option in its category:

Hosting: Railway Database: Neon Auth: Clerk Payments: Stripe Email: Resend Storage: R2 Monitoring: Sentry CI/CD: GitHub Actions Analytics: PostHog Jobs: Inngest
$0/month
Total infrastructure cost at launch (Stripe charges per-transaction only)
$0 covers the 9 of 10 picks whose free tier our own badge still reads as active. It does not cover Stripe (unrated — not a free offer).
1K users
~$40-80
10K users
~$150-300
100K users
~$500-1,500

Stack Overview

Category Recommended Key Limit Stability
🚀 Hosting & Deployment Railway Free plan: $0/month with one-time $5 credit (30-day trial), 1 vCPU, 0.5 GB RAM per service, 0.5 GB volume… active
🗄️ Database Neon Serverless Postgres with branching — free tier includes 100 CU-hours/month per project, 0.5 GB storage per… active
🔐 Authentication Clerk Drop-in auth with 50K monthly retained users free, unlimited apps active
💳 Payments & Billing Stripe Payment processing — no monthly fees, 2.9% + $0.30 per transaction. Full API, dashboard, and test mode free… unrated — not a free offer
📧 Email & Transactional Resend Developer-first email API — 3K emails/month free (100/day cap), 3 domains, 1K marketing contacts/month, 5 AI… active
📦 Object Storage Cloudflare R2 Object storage with zero egress fees — 10 GB storage, 1M writes, 10M reads/month free active
🐛 Monitoring & Error Tracking Sentry Developer tier: 1 user, 5K errors/month, 5M spans/month, 50 session replays, 5GB application logs, 1GB… active
⚙️ CI/CD GitHub Actions Free CI/CD for public repos (unlimited minutes). Private repos: 2,000 min/mo GitHub-hosted runners, 500 MB… active
📈 Analytics PostHog Product analytics — 1M events/month, 5K session replays, 1M feature flag requests, 100K error events, A/B… active
⏱️ Background Jobs & Queues Inngest Serverless workflow orchestration — 50K executions, 500K events ingested, 5 concurrent steps, 500 MB span… active

🏗️ Framework & Runtime

🚀 Hosting & Deployment

Recommended Railway Free active

The best all-around free hosting for SaaS in 2026. Its Free plan opens with a 30-day trial carrying $5 of credits and then costs $1/month minimum, enough for a small app with auto-deploy from GitHub. Supports any language/framework via Nixpacks or Dockerfile. No cold starts — your service stays warm. Includes free Postgres and Redis add-ons. Best DX: instant deploys, logs, and metrics in one dashboard.

Free plan: $0/month with one-time $5 credit (30-day trial), 1 vCPU, 0.5 GB RAM per service, 0.5 GB volume storage, 1 project, 3 services max ($1/month minimum after trial). Hobby plan: $5/month with $5 resource credit…

When you'll outgrow it: When you exceed the $5 of usage that Hobby's $5/month includes (1-2 services). Vercel is best for Next.js (100 GB bandwidth, but bans commercial use on Hobby plan — you must upgrade to Pro at $20/seat/month when you launch your SaaS). Render offers a free tier with 750 hours/month but spins down after 15 min inactivity. Cloudflare Pages is best for static/Jamstack with unlimited bandwidth.
⚠️ Why not Heroku: No free tier since November 2022. Why not Vercel Hobby: Bans commercial use — the moment your SaaS charges users, you owe $20/seat/month. Great for prototyping, but plan for the upgrade. Why not AWS/GCP/Azure directly: Free tiers exist but are complex to configure and most services expire after 12 months.
Full comparison guide →

🗄️ Database

Recommended Neon Free active

Serverless Postgres — the best SaaS database in 2026. 0.5 GiB storage, 190+ compute hours/month, scales to zero when idle. Branching for preview environments. Works with every ORM (Prisma, Drizzle, TypeORM, SQLAlchemy, pgx). Connection pooling handles concurrent users efficiently. Neon is what Vercel, Replit, and Retool use internally.

Serverless Postgres with branching — free tier includes 100 CU-hours/month per project, 0.5 GB storage per project, up to 100 projects, 10 branches per project, Neon Auth (60K MAU), auto-scaling up to 2 CU, scale-to-zero

When you'll outgrow it: When you exceed 0.5 GiB storage or need always-on compute. Supabase gives 500 MB Postgres with auth + storage + realtime bundled (pauses after 1 week inactive). CockroachDB offers 10 GiB distributed SQL — best for multi-region SaaS. Turso provides 9 GB edge SQLite — great for read-heavy, globally distributed apps.
⚠️ Why not MongoDB Atlas: 512 MB free, but document databases add complexity for SaaS (no joins, denormalized data, eventual consistency). Postgres handles 95% of SaaS workloads better. Why not PlanetScale: Removed free tier in April 2024.
Full comparison guide →

🔐 Authentication

Recommended Clerk Hobby active

50,000 monthly retained users free — the most generous managed auth for SaaS. Drop-in React/Next.js components for login, signup, user profile, and organization management. Social login, MFA, and RBAC included. Organizations feature (multi-tenant SaaS) available on free tier. Webhooks for syncing user data to your database.

Drop-in auth with 50K monthly retained users free, unlimited apps

When you'll outgrow it: When you exceed 50K retained users. Auth0 offers 25,000 MAU with enterprise features (M2M tokens, SSO). Kinde gives 10,500 MAU with feature flags bundled. Supabase Auth provides 50,000 MAU if you're already using Supabase for your database. At 100K users: Clerk ~$175/mo, Auth0 ~$240/mo, Supabase ~$25/mo (cheapest at scale).
⚠️ Why not Firebase Auth: 50K MAU free, but Firebase is a full BaaS — using just auth means importing the entire SDK. Supabase Auth is a better à la carte option. Why not rolling your own: Auth is the #1 source of security vulnerabilities in SaaS. Password reset, email verification, rate limiting, session management, CSRF — auth providers handle all of this. Only roll your own if you have dedicated security expertise.
Full comparison guide →

💳 Payments & Billing

Recommended Stripe No monthly fee — 2.9% + 30¢/txn unrated — not a free offer

The default SaaS billing platform. No monthly fees — only 2.9% + 30¢ per transaction. Subscriptions, usage-based billing, invoicing, tax calculation, customer portal, and webhooks. Every SaaS billing library (Stripe.js, @stripe/stripe-js) is built for Stripe first. Start collecting revenue on day one with zero fixed costs.

Payment processing — no monthly fees, 2.9% + $0.30 per transaction. Full API, dashboard, and test mode free. Pay only when processing live payments

When you'll outgrow it: You don't outgrow Stripe — it scales to billions. Consider Lemon Squeezy ($0 fixed + 5% + 50¢) if you need a Merchant of Record (handles sales tax, VAT, and compliance globally — you receive net payouts). Paddle (5% + 50¢) is the enterprise MoR alternative. The trade-off: MoR services charge higher per-transaction fees but eliminate tax/compliance complexity.
⚠️ Why not PayPal: Higher fees, worse developer experience, no native subscription billing. Why not building your own billing: Subscription billing has edge cases (proration, dunning, tax compliance, refunds, upgrades/downgrades) that take months to build correctly. Stripe handles all of this. Why not free alternatives: There aren't any — payment processing requires financial infrastructure.

📧 Email & Transactional

Recommended Resend Free active

3,000 emails/month free with a modern, developer-first API. React Email for templates — write email templates in JSX. Clean SDK, excellent deliverability, and webhook notifications for bounces and complaints. The new standard for SaaS transactional email (welcome emails, password resets, invoice notifications, team invitations).

Developer-first email API — 3K emails/month free (100/day cap), 3 domains, 1K marketing contacts/month, 5 AI credits, 30-day data retention

When you'll outgrow it: When you exceed 3,000 emails/month or 100/day. Brevo gives 300 emails/day (9,000/month) with marketing automation included — good for SaaS that needs both transactional and newsletter email. Amazon SES no longer has a free tier — cheapest at scale ($0.10/1K emails) but requires more setup.
⚠️ Why not SendGrid: Free tier removed May 2025. Many tutorials still reference it — those are outdated. Why not Mailgun: Free tier removed. Why not Postmark: No free production tier (test mode only). Postmark has the best deliverability but costs $15/mo for 10K emails.
Full comparison guide →

📦 Object Storage

Recommended Cloudflare R2 Free active

10 GB storage with zero egress fees — the only major storage provider that doesn't charge for bandwidth. S3-compatible API works with every SDK and library. For SaaS, this means user uploads (avatars, documents, images) cost nothing to serve, no matter how many times they're downloaded. No surprise bandwidth bills.

Object storage with zero egress fees — 10 GB storage, 1M writes, 10M reads/month free

When you'll outgrow it: When you exceed 10 GB storage or 1M Class A operations/month. R2's zero-egress model means the constraint is storage volume, not bandwidth — a SaaS serving 1 TB of user files still pays $0 in egress. At scale: 100 GB costs ~$1.50/mo on R2 vs ~$9/mo on S3 (plus $9/GB egress on S3). Backblaze B2 offers 10 GB free and free egress up to 3x what you store, no CDN required.
⚠️ Why not AWS S3: The 5 GB free tier expires after 12 months, then egress costs $0.09/GB. A SaaS serving user-uploaded files can accumulate significant egress costs. R2 charges $0 for egress, forever. Why not Vercel Blob: 250 MB free — too small for most SaaS file storage needs.
Full comparison guide →

🐛 Monitoring & Error Tracking

Recommended Sentry Developer active

5,000 errors/month, 10,000 performance transactions, 50 session replays, 1 GB attachments — all free. Best-in-class error tracking with stack traces, release tracking, and user context. Integrates with every framework (Next.js, Django, FastAPI, Go, Rails). Session replay shows you exactly what the user saw when the error occurred.

Developer tier: 1 user, 5K errors/month, 5M spans/month, 50 session replays, 5GB application logs, 1GB attachments

When you'll outgrow it: When you exceed 5,000 errors/month (fix your bugs first). For full observability beyond error tracking: Grafana Cloud offers 10K metrics series + 50 GB logs + 50 GB traces free. New Relic gives 100 GB data ingest/month (most generous, but limited to 1 user). BetterStack combines uptime monitoring with incident management.
⚠️ Why not Datadog: Free tier has 1-day metric retention — practically unusable. Per-host pricing ($15/host/month) gets expensive fast. Why not just console.log: You'll miss errors in production, have no alerting, and can't see trends. Sentry catches errors you didn't know about.
Full comparison guide →

⚙️ CI/CD

Recommended GitHub Actions Free active

2,000 minutes/month for private repos, unlimited for public. Deep GitHub integration — trigger on push, PR, schedule, or manual dispatch. Massive marketplace of community actions for testing, linting, deploying, and security scanning. Matrix testing across Node/Python/Go versions. Cache dependencies to cut build times by 50-80%.

Free CI/CD for public repos (unlimited minutes). Private repos: 2,000 min/mo GitHub-hosted runners, 500 MB artifact storage, 10 GB cache/repo. Self-hosted runners remain free — planned $0.002/min charge was postponed…

Also consider:

GitLab CI Free active
When you'll outgrow it: When you exceed 2,000 minutes/month on private repos. Self-hosted runners are free (but now cost $0.002/min for private repos as of March 2026). Railway and Vercel auto-deploy from git — combine with GitHub Actions for tests only to conserve minutes.
Full comparison guide →

📈 Analytics

Recommended PostHog Free active

1M events/month, 5K session replays, feature flags, and A/B testing — all free. The most comprehensive product analytics platform for SaaS. Track user journeys, measure feature adoption, run experiments, and manage feature rollouts. Self-hostable (open source). GDPR-friendly with EU hosting option.

Product analytics — 1M events/month, 5K session replays, 1M feature flag requests, 100K error events, A/B testing. No credit card required

When you'll outgrow it: When you exceed 1M events/month — typically at 10K-50K active users depending on event density. Plausible (self-hosted) is free with unlimited events but only covers web analytics (no funnels, no feature flags). Umami (self-hosted) is similar. For SaaS, PostHog's product analytics + feature flags combination is hard to beat.
⚠️ Why not Google Analytics: Privacy concerns, complex setup, no feature flags or session replay. Many SaaS users block GA. Why not Mixpanel: Free tier is generous (20M events) but no session replay, feature flags, or A/B testing. PostHog bundles everything.
Full comparison guide →

⏱️ Background Jobs & Queues

Recommended Inngest Hobby active

Free tier: 25,000 function runs/month with 5 concurrent steps. Durable workflow orchestration — retries, scheduling, fan-out, and step functions. TypeScript-first with Next.js integration. No infrastructure to manage — send an event, Inngest runs your function reliably. Perfect for SaaS: onboarding workflows, scheduled reports, webhook processing, billing reconciliation.

Serverless workflow orchestration — 50K executions, 500K events ingested, 5 concurrent steps, 500 MB span data ingested, 100K queue depth, 50 realtime connections

When you'll outgrow it: When you exceed 25,000 runs/month. Trigger.dev offers 10,000 runs/month free with a similar developer experience. For simpler needs: Upstash QStash (500 messages/day free) provides HTTP-based async messaging — send a POST, it delivers reliably with retries. For self-managed: BullMQ (Redis-backed) with Upstash Redis (10K commands/day) handles moderate queue needs.
⚠️ Why not cron jobs alone: Cron doesn't retry failures, handle concurrency limits, or provide observability. Why not AWS SQS/Lambda: Complex setup, 12-month free tier expiration. Inngest and Trigger.dev give you managed, durable execution with a serverless DX.

Stability Notes

Recent pricing changes affecting vendors in this stack. Based on our tracking of 554 deal changes across 1,547+ developer tools.

limits reduced Supabase: Project pause policy tightened — inactive projects now pause after 1 week Source ↗
pricing postponed GitHub Actions: Self-hosted runner per-minute fee ($0.002/min) announced for March 2026 was postponed indefinitely after community backlash. Self-hosted ... Source ↗
pricing restructured Sentry: Switched from performance units to spans-based metrics for error and performance monitoring Source ↗
pricing restructured Neon: Moved to fully usage-based pricing model post-Databricks acquisition — free tier storage now per-project, projects increased 10→100, bran... Source ↗
pricing restructured Vercel: Pro plan moved to credit-based model ($20/mo credit pool), Hobby plan metrics renamed and restructured — bandwidth→Fast Data Transfer, se... Source ↗
limits increased Auth0: Auth0 increased free tier from 7,500 to 25,000 monthly active users. Largest free tier expansion since Okta acquisition. Makes Auth0 comp... Source ↗
limits increased Railway: Railway expanded free tier following $100M Series B. Trial plan now includes $5 in free credits/month, sufficient for small hobby project... Source ↗
limits reduced Render: Free web services now spin down after 15 minutes of inactivity (previously 30 minutes). Cold starts take 30-60 seconds. Free tier remains... Source ↗
pricing restructured Vercel: New Pro projects now default to Turbo build machines (30 vCPUs, 60GB memory) at $0.126/minute — 9x more expensive than Standard machines ... Source ↗
free tier removed Amazon SES: AWS restructured its Free Tier into expiring credits, which removed the per-service SES allowance for new accounts. The SES pricing page,... Source ↗
free tier removed Plausible Analytics: The page highlights open source and privacy-friendly aspects, it primarily focuses on paid plans starting at $9/month. A free trial is of... Source ↗
limits increased Inngest: The event limit has increased from 100K to 500K, and the span data ingested limit has increased from 100MB to 500MB. The number of users ... Source ↗

View all 554 pricing changes →

The Growth Path — From $0 to $500/Month

What you'll spend at each scale milestone. The most expensive moment is the first upgrade — plan for it.

Scale Users Monthly Cost What Changes
🚀 Launch 0-500 $0/mo Everything on free tiers. Stripe charges only per transaction.
📈 Traction 1K-5K $40-80/mo Database ($19) and hosting ($5-20) are the first upgrades. Email may hit limit at 3K sends/month. Auth, analytics, monitoring still free.
🔥 Growth 10K-25K $150-300/mo Email upgrade ($20), analytics may exceed 1M events, monitoring upgrade ($26). Auth still free (Clerk 50K, Auth0 25K). Hosting scales with usage.
🏢 Scale 50K-100K $500-1,500/mo All services on paid tiers. Auth exceeds free limits. Database at Scale tier ($69). Analytics, monitoring, background jobs all paid. But at 100K users, you should have significant revenue.

The $19/month breakpoint: Database (Neon Launch at $19/mo) is the first upgrade most SaaS products need — 0.5 GiB fills up fast with user data, session logs, and analytics tables. Everything else stays free much longer. Auth (Clerk 50K free) and analytics (PostHog 1M events) typically last until 10K+ active users. Key insight: at every scale point, your infrastructure cost should be <10% of revenue. If you're charging $10/user/month, 100 users = $1,000 MRR — more than enough to cover $40-80/month in infrastructure.

When to Upgrade — Service by Service

Sorted by which limits you'll likely hit first:

Layer Free Limit First Paid At 100K Users
Database ⬆ hit first 0.5 GiB Launch $19/mo $69/mo (Scale)
Hosting ⬆ hit first $1/mo min after 30-day $5 trial Hobby $5/mo $20+/mo (usage)
Email 3K/mo Pro $20/mo $100/mo (100K)
Auth 50K MRU $25/mo $175/mo (100K)
Analytics 1M events Pay-as-you-go $450/mo
Storage 10 GB $0.015/GB/mo $15/mo (1TB)
Monitoring 5K errors Team $26/mo $80/mo
Payments No fixed cost 2.9% + 30¢/txn 2.9% + 30¢/txn
Background Jobs 25K runs/mo $50/mo $150/mo
CI/CD 2K min/mo Team $4/user/mo $19/user/mo

Need a specialized stack? See our Free Startup Stack for general infrastructure, Free AI/ML Stack for AI development, or Free DevOps Stack for infrastructure tooling. Framework-specific guides: Next.js · Django · FastAPI · Go. Or search our full index of 1,547+ developer deals.

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