How to Pick the Best Database for a Marketplace App
A practical comparison of Supabase, Firebase, and Convex for an app with listings, sellers, offers, messages, images, and room to grow.
The short version
For a marketplace, I would choose Supabase. A marketplace is fundamentally a set of related records: users own listings, listings have images and offers, buyers save items, and orders connect multiple people. PostgreSQL and SQL are a strong fit for those relationships and the filtering users expect.
Firebase is still an excellent choice when getting an MVP shipped quickly matters most, especially if you already know it. Convex is a compelling option for a modern React team that values realtime updates and a type-safe developer experience over ecosystem maturity.
At a glance
| Platform | MVP speed | Marketplace fit | Images | Learning curve | Overall |
|---|---|---|---|---|---|
| 🥇 Supabase | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★☆☆ | 9.8/10 |
| 🥈 Firebase | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★★ | 9.2/10 |
| 🥉 Convex | ★★★★★ | ★★★★☆ | ★★★★☆ | ★★★★☆ | 8.8/10 |
1. Supabase: the best long-term fit
This would be my choice. Supabase gives you a hosted PostgreSQL database alongside authentication, file storage, realtime features, and a strong TypeScript workflow. The important part is the relational core: joins, indexes, constraints, and SQL make marketplace queries natural.
A query such as “show all 1:64 Hot Wheels under €20 from Irish sellers, newest first” is exactly the sort of query that benefits from a relational schema and carefully chosen indexes. You can model sellers, listings, categories, locations, currencies, and offers separately without flattening everything into one document shape.
Why it works well
- Relational data is a natural fit for listings, favourites, offers, messages, reviews, and orders.
- SQL makes filtering, searching, sorting, and reporting easier to extend.
- Built-in authentication and storage cover common marketplace foundations.
- Row Level Security is excellent for multi-user apps where buyers, sellers, and admins need different access.
- Realtime updates are available when chat, offer status, or inventory needs them.
- The PostgreSQL foundation keeps a self-hosting or migration path open if your requirements change.
The trade-off
Supabase asks you to learn some SQL and think carefully about schema design, indexes, and policies. Offline behaviour also takes more deliberate application work than Firebase’s typical mobile workflow.
Best for: user accounts, listings, favourites, offers, messages, reviews, orders, and an admin dashboard. Future scalability: 10/10.
2. Firebase: the fastest familiar MVP
If you already know Firebase, you can be productive immediately. Firestore, Firebase Authentication, and Cloud Storage integrate especially well with Expo and React Native, and Firestore’s realtime listeners make responsive mobile screens quick to build.
Why it works well
- Excellent Expo integration and a gentle path to a working mobile MVP.
- Authentication is straightforward to add.
- Offline support and realtime updates are strong selling points.
- Cloud Storage is a good fit for listing images.
Where it gets harder
As the marketplace grows, Firestore’s document model and query constraints can make complex discovery, reporting, and cross-entity filtering more awkward. You can solve many cases with denormalisation and carefully designed indexes, but the data model may become more demanding to maintain.
Best for: a fast MVP, mobile-first apps, realtime updates, and offline support. Future scalability: 8/10.
3. Convex: a delightful React-first option
Convex is a newer backend option that feels very natural to React developers. It combines a type-safe data layer, realtime updates, and server functions without asking you to write traditional SQL.
Why it works well
- Excellent developer experience with a tight React and React Native feedback loop.
- Realtime behaviour is built into the model.
- Type-safe queries and mutations reduce the gap between client and backend.
- You can build a modern product quickly without managing a traditional API layer.
Keep the trade-offs in view
Convex has a smaller ecosystem and fewer long-established tutorials than Supabase or Firebase. Its abstractions are productive, but they also create more vendor lock-in. That may be a reasonable trade for a small team; it is worth making consciously.
Best for: modern React apps where developer experience, type safety, and realtime behaviour are the top priorities.
My recommendation
Choose Supabase if you expect the product to become a real marketplace with increasingly specific search, moderation, reporting, and transaction workflows. The relational model gives you a solid foundation for the questions the business will ask later.
Choose Firebase if the immediate goal is to validate the idea quickly, your team already knows Firebase, or offline-first mobile behaviour is a defining feature. Choose Convex if your team is strongly React-oriented and the productivity benefits outweigh the smaller ecosystem.
Whichever option you choose, design the boundaries early: keep image files in object storage, enforce access in backend rules or policies, add indexes for real user queries, and test the flows that cross users—offers, messages, reviews, and orders—before launch.