Database & Backend Platform · decision tool
Best backend for a mobile app
The BaaS/backend options for mobile — Supabase, Firebase, Convex and more — ranked at your users, data and budget with verified pricing. Reuses the database engine; realtime/offline needs are scored where they matter.
Prices verified 2026-07-15 against official pricing pages · fit weights are our estimates (see methodology) · share the URL to share your configuration
As of Jul 2026, with 20,000 monthly active users, 5 GB database size, 40 GB monthly egress, 1,000 db operations per user / month, 24 compute active hours / day, a $25 budget for this slot, Supabase ranks first for these inputs at 84% fit and a StackSays-estimated $25.00/month (Firebase (Firestore): 82% fit, $19.90/month). Fit weights are our estimates; prices trace to official pages. Change any input below and the verdict recomputes.
Your situation
The verdict updates as you move these.
Toss-up — your priorities decide, not the tools
Managed Postgres bundled with auth, realtime, storage and edge functions
vs Firebase (Firestore): fit 84% against 82%, est $25.00 against $19.90 per month — genuinely close; read both risk lists below
The decision, in plain words
For a solo builder at 20,000 monthly active users and a $25.00/mo budget for the database slot, Supabase leads at 84% fit and $25.00/mo. The two rules doing the work: budget fit (~$25/mo is 100% of your $25/mo budget); batteries included (Bundles auth, file storage, realtime — fewer services to glue at team size 1).
Firebase (Firestore) is a genuine coin-flip here (82% fit, $19.90/mo, $5.10 cheaper) — read both risk lists and pick the failure mode you prefer.
Ruled out entirely: Neon (no built-in realtime — you said you need it); Turso (no built-in realtime — you said you need it); PlanetScale (no built-in realtime — you said you need it); MongoDB Atlas (no built-in realtime — you said you need it) — hard requirements, not scoring.
Generated from the calculation above — every number traces to the sourced data; nothing here is written by an AI making things up.
Why Supabase scores 84%
How the $25.00/mo estimate is calculated
What could change this verdict
Cost risk
Official prices verified 2026-07-15; calculation is deterministic code over those prices.
At a glance
| Tool | Free tier | Paid entry | Verified |
|---|---|---|---|
| Supabase | 500MB database, 50K MAU, 1GB file storage, 5GB egress, 2 projects | Pro plan $25/mo | 2026-07-15 |
| Neon | 0.5GB storage + 100 compute-hours per project, 5GB egress, 60K auth MAU | Pay-as-you-go — Compute billed per CU-hour ($0.106); suspended compute costs $0; storage $0.35/GB-month | 2026-07-15 |
| Firebase (Firestore) | 1GiB Firestore, 50K reads / 20K writes / 20K deletes per day, 50K auth MAU, 10GiB egress | Pay-as-you-go — Firestore nam5 rates: $0.06/100K reads, $0.18/100K writes, $0.18/GiB storage; deletes ($0.02/100K) not modeled. Ops derived from your per-user activity input (80/20 read/write split, our estimate) | 2026-07-15 |
| Convex | 1M function calls, 0.5GB database, 1GB file storage, 1GB egress | Professional $25/mo | 2026-07-15 |
| Turso | 100 databases, 5GB storage, 500M rows read / 10M rows written per month | Developer plan $4.99/mo | 2026-07-15 |
| PlanetScale | No free tier | PS-5 HA cluster $15/mo | 2026-07-15 |
| MongoDB Atlas | 512MB storage, shared CPU/RAM, ~100 ops/sec cap | Flex tier $8/mo | 2026-07-15 |
Data sources
| Tool | Source | Verified |
|---|---|---|
| Supabase | Supabase pricing page | 2026-07-15 |
| Neon | Neon pricing page | 2026-07-15 |
| Firebase (Firestore) | Firebase pricing page | 2026-07-15 |
| Convex | Convex pricing page | 2026-07-15 |
| Turso | Turso pricing page | 2026-07-15 |
| PlanetScale | PlanetScale pricing page | 2026-07-15 |
| MongoDB Atlas | MongoDB Atlas pricing page | 2026-07-15 |
A monitor re-checks these pages for changes; when a vendor moves a price, the date updates and every verdict recomputes.