Firebase Alternatives for SaaS in 2026: Supabase, AWS Amplify, and Custom

We migrated 3 SaaS apps off Firebase. Here is when to stay, when to leave, and what to switch to.

By David Friedman, Founder of AppBrewers

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Firebase is the default backend for MVPs. But at 10,000+ users, costs spike and limitations appear. We migrated 3 SaaS apps off Firebase in 2025. Two went to Supabase. One went custom. Here is how to decide.

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When Firebase Is Perfect

Stage	Users	Firebase Cost	Why It Works
MVP	0-1,000	0-50 Euro/month	Free tier covers everything.
Growth	1,000-10,000	50-300 Euro/month	Still cheap, still scalable.
Scale	10,000-50,000	300-1,500 Euro/month	Costs rise but manageable.
Enterprise	50,000+	1,500-5,000 Euro/month	Time to evaluate alternatives.

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Firebase Limitations at Scale

Limit	Impact	Workaround
Firestore query limitations	Complex joins are hard	Denormalize data
Cloud Functions cold starts	2-5 second latency	Keep functions warm
Vendor lock-in	Hard to migrate	Abstract data layer early
Real-time costs	100K+ concurrent connections gets expensive	Use polling for low-frequency updates
No SQL support	Analytics queries are slow	Export to BigQuery

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The Alternatives

Supabase

Factor	Supabase	Firebase
Database	PostgreSQL	Firestore (NoSQL)
Real-time	Yes	Yes
Auth	Yes	Yes
Storage	Yes	Yes
Edge functions	Yes	Cloud Functions
Self-hosting	Yes	No
SQL queries	Yes	No
Pricing	Cheaper at scale	Cheaper at start

Best for: Teams that need SQL, complex queries, or want to self-host.

AWS Amplify

Factor	Amplify	Firebase
Ecosystem	AWS services	Google services
Flexibility	High	Medium
Complexity	High	Low
Enterprise features	Extensive	Limited
Team size needed	2+ backend devs	0-1 backend devs

Best for: Enterprise apps, teams with AWS expertise.

Custom Backend (Node.js + PostgreSQL)

Factor	Custom	Firebase
Control	Total	Limited
Cost at scale	Lower	Higher
Development time	2-3x longer	Fast
Maintenance	Requires dedicated backend dev	Minimal
Flexibility	Unlimited	Platform-defined

Best for: Apps with 100K+ users, complex business logic, or regulatory requirements.

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Our Migration Decision Tree

Are you building an MVP?
  Yes -> Use Firebase
  No -> Are you over 50K users?
    Yes -> Consider custom backend
    No -> Do you need complex SQL queries?
      Yes -> Supabase
      No -> Stay on Firebase

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Migration Costs

From	To	Timeline	Cost	Risk
Firebase	Supabase	2-4 weeks	3,000-8,000 Euro	Low
Firebase	AWS Amplify	4-8 weeks	8,000-15,000 Euro	Medium
Firebase	Custom backend	8-16 weeks	15,000-40,000 Euro	High

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Need Help Choosing?

We have built on Firebase, Supabase, and custom backends. We will tell you which fits your stage and budget.

• appbrewers.com/get-a-quote
• [e-mail]

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Originally published on the AppBrewers Blog.