Convex vs PostgreSQL for Solo Developers

Quick Comparison

Convex Overview

Convex is a backend platform where your database, server functions, file storage, and realtime sync all live under one roof. You write TypeScript functions that run on Convex's servers, and the platform automatically keeps every connected client in sync when data changes. No WebSocket code, no manual cache invalidation, no API routes to maintain.

For solo developers, Convex collapses the entire backend into a set of functions. Your schema defines types that propagate through your functions into your React components. The development experience is smooth: change a mutation, see the effect in your running app immediately.

The free Starter plan gives you 1 million function calls, 0.5 GB of database storage, 1 GB of file storage, and 1 GB of egress per month, with seats for 1 to 6 developers. Go past those limits and you stay on the same plan but pay as you go, for example 2.20 dollars per additional million function calls and 0.22 dollars per additional GB of database storage. That covers the build phase and early users comfortably before you ever reach for the paid Professional tier.

PostgreSQL Overview

PostgreSQL is the most advanced open-source relational database. It supports standard SQL along with JSON columns, full-text search, PostGIS for geospatial data, materialized views, CTEs, window functions, and a long list of features that other databases are still catching up on. It has been in active development since 1996 and it shows.

For solo developers, Postgres is the default choice for a reason. It works with every language, every framework, and every deployment model. You can self-host it, use managed services like Neon (free tier), Supabase (free tier), Railway ($5/mo), or AWS RDS. The tooling ecosystem is the largest of any database.

Postgres is free and open source with no usage limits. A solo developer can run it on a $5 VPS and handle thousands of concurrent users without paying for a managed service.

Head-to-Head Comparison

By the Numbers (2026)

Voice and verdict are one thing. Here are the figures that should anchor the decision, all checked on 2026-05-28.

Convex

• Client library convex on npm is at version 1.39.1, licensed Apache-2.0.
• That package pulls roughly 731,000 downloads per week on npm, so the ecosystem is real but still an order of magnitude smaller than the Postgres client world.
• The self-hostable get-convex/convex-backend repository sits at about 11,700 GitHub stars and is written in TypeScript (with a Rust core).
• Free Starter limits: 1 million function calls, 0.5 GB database storage, 1 GB file storage, 1 GB egress, and 1 to 6 developer seats.
• Professional is 25 dollars per developer per month and raises the included limits to 25 million function calls, 50 GB database storage, 100 GB file storage, and 50 GB egress. Overages on Professional run 2 dollars per additional million function calls and 0.20 dollars per additional GB of database storage.

PostgreSQL

• The current major release is PostgreSQL 18, which shipped on September 25, 2025. The latest minor release is 18.4, dated May 14, 2026.
• The official source repository (the postgres/postgres GitHub mirror) carries about 21,000 stars, and the engine itself is written in C.
• PostgreSQL 18 added asynchronous I/O, virtual generated columns, native UUIDv7 generation, skip scans on multicolumn B-tree indexes, and OAuth 2.0 authentication support.
• The database is free and open source with no usage limits when you self-host. Managed free tiers are easy to find: Neon gives you 0.5 GB of storage per project plus 100 compute-hours, and Supabase gives you a 500 MB database, 1 GB of file storage, and 5 GB of egress on its free plan.
• The Postgres client ecosystem dwarfs everything else here. The pg driver alone does roughly 29 million npm downloads per week, with prisma near 11.6 million and drizzle-orm near 9.6 million. Whatever language or ORM you choose, the road is well paved.

The star and download gap is not a quality judgment, it is a portability judgment. Postgres skills and tooling carry to nearly any stack, while Convex skills carry to Convex.

Real Cost at Solo-Dev Scale

Pricing tables hide the answer most solo developers actually want, which is what they will pay once a small app has real users. Here is a worked example for a modest production workload, using the published per-unit rates above.

Assumptions for one solo developer, one app, one month

• 1 seat (just you).
• 8 million function calls or API requests across the month (a small-but-live app, roughly 3 requests per second at peak with normal idle time).
• 2 GB of database storage.
• 5 GB of file storage and 5 GB of egress.

Convex

You exceed the free Starter call limit (1 million), so you move to Professional at 25 dollars per developer per month, which includes 25 million function calls, 50 GB database storage, 100 GB file storage, and 50 GB egress. Your workload sits comfortably inside every included limit, so there are no overages. Total is 25 dollars per month. The number stays at 25 dollars until you cross 25 million calls or 50 GB of data, at which point overages of 2 dollars per million calls kick in. The clean part of the Convex deal is that this single price also covers your backend functions and realtime sync, which on Postgres you build or buy separately.

PostgreSQL

There are three honest paths:

• Self-host on a small VPS. A 5 to 6 dollar per month instance comfortably holds 2 GB of data and this request volume. Call it about 6 dollars per month, plus your own time for backups, upgrades, and monitoring.
• Neon managed Postgres. The free tier caps at 0.5 GB storage, and 2 GB of data pushes you onto a paid plan that starts around 19 dollars per month, so figure roughly 19 dollars plus any compute overage.
• Supabase. The free tier caps at 500 MB database size, so 2 GB moves you to Supabase Pro at 25 dollars per month, which also bundles auth, storage, and realtime.

The honest read. At this scale Convex and Supabase Pro land at the same headline number, 25 dollars per month, because both bundle a backend, not just a database. Raw self-hosted Postgres is the cheapest in dollars (around 6 dollars) and the most expensive in your hours. Neon sits in between on price but keeps your data in standard Postgres. So the cost question is really a packaging question: pay Convex or Supabase for an integrated backend, or pay less to Neon or a VPS and assemble the backend yourself.

When to Pick Convex

Pick Convex when you are building a React application and the development experience matters more to you than long-term flexibility. Convex's tight integration with React makes building interactive, realtime applications feel effortless. You write functions, call hooks, and everything stays in sync.

It is the right choice when your application is inherently realtime. Collaborative document editors, multiplayer games, live auction platforms, team chat tools: these applications need every user to see the same state simultaneously. Convex makes this the default behavior rather than a feature you build.

Choose Convex when you are prototyping or validating an idea quickly. The time savings of not building an API layer can be the difference between launching this week and launching next month. For a solo developer testing product-market fit, that speed matters.

When to Pick PostgreSQL

Pick PostgreSQL when you want the most capable, flexible, and portable database available. Postgres handles relational data, JSON data, full-text search, geospatial queries, time-series data, and vector embeddings (via pgvector). Whatever your application needs, Postgres probably has a feature for it.

It is the right choice when your data model is complex and relational. If you need to join five tables, aggregate data across millions of rows, or enforce complex referential integrity, SQL is the tool for the job. No document database can match the query power of a well-designed Postgres schema.

Choose PostgreSQL when vendor independence is important. Your data lives in a standard database that any tool can connect to. You can switch hosting providers, change ORMs, rebuild your entire backend in a different language, and your database stays exactly the same.

PostgreSQL is also the right choice when you are building something that needs to last. Postgres has been reliable for 30 years. The community is enormous. The documentation is comprehensive. And your skills transfer to any company or project that uses it, which is most of them.

The Verdict

This is a choice between speed of development and breadth of capability.

Convex gets you to a working product faster if you are building a React application with realtime features. The platform handles backend concerns that would take weeks to build yourself. The trade-off is vendor lock-in and a smaller feature set compared to Postgres.

PostgreSQL gives you the most powerful database available with zero lock-in. The trade-off is that you need to build your own API layer, handle realtime yourself (or use Supabase), and manage more infrastructure.

For most solo developers, I would recommend starting with PostgreSQL through a managed service like Neon or Supabase. Both have free tiers, both work with Drizzle or Prisma for type-safe queries, and Supabase even adds realtime subscriptions and auth on top. This gives you a similar development speed to Convex while keeping your data in a standard database.

If you specifically want the Convex development experience and you are building a React app where automatic reactivity saves you significant time, Convex is worth trying. Just go in knowing that your backend code and data model are tied to the platform.

Sources

All figures checked on 2026-05-28.

• Convex pricing and Starter and Professional limits: convex.dev/pricing
• Convex plan and usage limits reference: docs.convex.dev/production/state/limits
• Convex client version 1.39.1 and Apache-2.0 license: registry.npmjs.org/convex/latest
• Convex npm weekly downloads (about 731,000): api.npmjs.org/downloads/point/last-week/convex
• Convex self-host repo stars (about 11,700): github.com/get-convex/convex-backend
• PostgreSQL 18 release and feature set (September 25, 2025): postgresql.org PostgreSQL 18 Released
• PostgreSQL 18.4 minor release (May 14, 2026): postgresql.org 18.4 release announcement
• PostgreSQL source mirror stars (about 21,000): github.com/postgres/postgres
• pg driver npm weekly downloads (about 29 million): api.npmjs.org/downloads/point/last-week/pg
• drizzle-orm npm weekly downloads (about 9.6 million): api.npmjs.org/downloads/point/last-week/drizzle-orm
• Neon managed Postgres free tier and Launch plan pricing: neon.com/pricing
• Supabase free tier and Pro plan pricing: supabase.com/pricing