SaaS vs PaaS

SaaS and PaaS are two layers of the cloud stack. The line between them is who builds the application — your team, or the vendor.

The key difference: SaaS gives you a finished application. PaaS gives you a platform to build your own application on.

DimensionSaaSPaaS
You consumeA finished app (Salesforce, Slack, Notion)A platform (Vercel, Heroku, Supabase)
You manageConfiguration, users, dataYour application code on top
Vendor managesEverything below the appRuntime, scaling, OS, infra
BuyerBusiness team — sales, marketing, opsEngineering team
Lock-in shapeData + workflowsRuntime + APIs

When to use SaaS

Choose SaaS when the problem is generic enough that someone has already built it well.

When to use PaaS

Choose PaaS when you're building something custom and want to skip infrastructure work.

FAQs

Where does IaaS fit?

IaaS (AWS EC2, GCP Compute) is one layer lower — raw infrastructure. PaaS sits on top of IaaS; SaaS sits on top of PaaS.

Is Supabase SaaS or PaaS?

PaaS — it gives you a managed Postgres, auth and storage platform that your application is built on, rather than a finished end-user app.

Can a product be both?

Yes. Many modern platforms (Shopify, Notion) expose APIs and an app surface, blurring the line — buyers still classify them by primary use.