Answer six quick questions about workload, real-time needs, branching, geography, bundling, and size. Get back one recommended database from Supabase, Neon, Turso, Vercel Postgres, PlanetScale, Cloudflare D1, Convex, or Firebase — with two runner-ups and an estimated monthly cost for each.
Methodology. Pricing verified against vendor sites as of June 2026. The picker uses deterministic decision rules — no AI black box. Recommendations are a research synthesis of public docs and community reports, not first-person hands-on tests. Use the override section below if your situation doesn’t fit the defaults.
Your winner is highlighted. Yes/partial/no marks each database against the requirements implied by your answers.
The picker is a deterministic decision tree, not an AI black box. Six answers feed into a hand-curated rule table that maps your workload to one of eight named databases — Supabase, Neon, Turso, Vercel Postgres, PlanetScale, Cloudflare D1, Convex, or Firebase. The logic is decision-first: your workload tells us which database fits; the cost is a secondary verification, not the primary input. If you want the picker that leads with cost, use the Supabase vs Neon cost calculator instead. This one is for the moment when you’ve decided to ship and you need a defensible single pick.
Each rule is ordered. Real-time as a core feature beats every other dimension because retrofitting WebSockets onto a database that doesn’t support live subscriptions is the most expensive class of architectural mistake we see. Below that, the rule order is: branching from day 1, edge global reads, bundled stack preference, then scale-and-write-heavy as the heavyweight fallback. If none of those rules fire, the picker falls back to Supabase for bundled use cases and Neon for database-only use cases — the two safest defaults in 2026 for solo SaaS.
These eight cover the realistic decision space for a solo or two-person SaaS in 2026. There are dozens of other Postgres providers, NoSQL stores, and edge databases, but for a founder shipping a product this year, the answer is almost always going to be one of these eight. Supabase and Neon are the two dominant managed-Postgres options, with Supabase winning on bundled features (auth, storage, functions, real-time) and Neon winning on branching, serverless scale-to-zero, and pure Postgres ergonomics. Turso and Cloudflare D1 represent the edge-SQLite category — globally distributed reads, small footprint, low cost — with Turso winning on flexibility and D1 winning on integration with the Cloudflare Workers stack.
Vercel Postgres is mechanically Neon underneath since the Q4 2024 transition, but the Vercel-native deploy flow (auto env vars, one bill, one dashboard) is worth a separate listing because the user experience meaningfully differs. PlanetScale is the heavyweight for MySQL-compatible workloads with massive scale and Vitess sharding built in — relevant when you genuinely have 50+ GB of data and high write throughput. Convex is a TypeScript-first reactive database that bundles real-time, functions, and storage in one platform with strong DX; it’s the right call for greenfield TypeScript apps where SQL compatibility isn’t a priority. Firebase remains the obvious answer for mobile-first apps with heavy real-time needs and Google ecosystem alignment, even though its SQL story is non-existent and the vendor lock is real.
The picker’s default fallback is Supabase for bundled use cases and Neon for database-only use cases. Five concrete scenarios will (and should) override the default.
1. You’re building real-time collaboration as the product, not a feature. Chat apps, multiplayer canvases, live dashboards where two users edit the same row at the same time. Supabase’s real-time subscriptions handle this in their default tier, but if you’re going bundled-stack-from-day-one and want every concurrent user covered without thinking about a separate WebSocket service, the picker will favor Supabase or Convex over Neon-style standalone Postgres.
2. You need branching environments per PR. If your team workflow requires every pull request to spin up a fresh database with seeded data, Neon is the only Postgres provider where branching is a first-class day-one feature, not an enterprise upsell. Vercel Postgres inherits this from Neon. PlanetScale offers branching for MySQL workloads. Supabase’s preview branching is younger and limited — functional but not the same workflow polish.
3. You’re selling globally and reads from Sydney can’t take 200ms. US/EU-only US-East deployments are fine for most B2B SaaS. The moment your B2C audience spans LATAM and APAC, edge-SQLite (Turso or Cloudflare D1) gives you single-digit-millisecond reads on every continent without managing replicas. The tradeoff is SQLite’s slightly weaker story on complex joins and the constraint that writes still go to a primary region.
4. You’re going to genuinely outgrow 50 GB in 12 months and write-heavy. Event logging, IoT-style ingestion, social feeds with millions of posts. PlanetScale’s Vitess sharding handles this category natively. Supabase Pro is fine to about 100 GB but starts to hurt on cost per GB. Neon scales, but at 50 GB+ with heavy writes the CU-hours add up.
5. You’re mobile-first and the iOS/Android SDKs decide it. Firebase’s SDKs for iOS, Android, and React Native are still the most polished in 2026, with offline persistence, real-time sync, and analytics tied in. If you’re shipping a mobile app and SQL queries are not your top priority, Firebase is the right call — vendor lock acknowledged.
The picker is opinionated and that’s the point — opinions ship, indecision doesn’t. But there are situations where you should ignore the recommendation. If your team has deep operational expertise in a database the picker doesn’t list (CockroachDB, FaunaDB, MongoDB Atlas, AWS RDS, Aurora), that expertise is worth more than the picker’s ranking. If you have an existing schema and migration cost to a different vendor is measured in weeks, stay where you are unless the destination is meaningfully better, not just nominally cheaper.
If your funding situation lets you pay for managed everything, the picker leans toward Supabase or Convex for bundled experience. If you’re running on free tiers and engineering hours are your scarcest resource, the picker leans toward whichever vendor has the most generous free tier for your specific workload — usually Supabase, Turso, or Neon depending on whether you’re bundled, edge-distributed, or pure Postgres. Read the rationale on the result card carefully; if a single answer feels weak, change it and re-run.
One last note on cost estimates. The picker shows an estimated monthly cost band per database at your stated size, but pricing for usage-based vendors (Neon, Firebase, D1, Vercel Postgres) is sensitive to traffic patterns we can’t infer from six questions. A 5 GB Neon database with constant 24/7 traffic costs roughly double the same database with intermittent traffic, because Neon’s scale-to-zero saves real CU-hours when nobody’s connected. Firebase’s Blaze plan is similar: at $0.18 per 100K reads, a chatty client that re-fetches on every keystroke can burn through your budget faster than the storage cost would suggest. The bands shown are a reasonable midpoint for a solo SaaS workload, not a quote. Treat them as a sanity check on the winner, not a finalized bill.
And remember the meta-point: the right database is the one your team can ship with this quarter. Migrating later is annoying but not fatal. Picking the perfectly optimal database and not shipping the product is fatal.
The stack, prompts, pricing, and mistakes to avoid — for solo founders building with AI.