Guides · For businesses
Self-hosted vs Firebase vs Retool: what a business backend really costs
Three common ways to give a small business its own system: build on Firebase, build internal tools in Retool, or run a backend on your own server. Here's what each really costs, with real prices, and when each one is the right choice. We make BackendGen.dev, so we've kept to published prices and said where the others are the better pick.
Prices checked on 7 November 2026, in US dollars unless stated. Sources are at the end.
The short answer
- Firebase is rarely expensive for a small business. Its free allowance covers a portal and bookings for a small team many times over. The real cost is building the app on top of it.
- Retool's cost grows with your team. It's quick for internal tools, but every person pays every month, for as long as you use it.
- Self-hosting costs once, plus a small server. It's usually the cheapest over a few years, and your data stays with you. The catch: someone has to look after the server.
Firebase: pay as you go
Firebase is Google's hosted backend: a database (Cloud Firestore), sign-in, hosting and server functions. You build your app on it and pay for what you use. There's no monthly subscription; the Blaze plan bills usage above a free allowance.
| Cloud Firestore | Free each day | Then |
|---|---|---|
| Document reads | 50,000 | $0.03 per 100,000 |
| Document writes | 20,000 | $0.09 per 100,000 |
| Document deletes | 20,000 | $0.01 per 100,000 |
| Stored data | 1 GiB in total | billed per GiB stored |
A busy app with 2 million reads and 500,000 writes a day would pay roughly $17.55 a month for reads and $12.96 for writes. A small business portal does a tiny fraction of that and usually pays nothing for the database at all. Sign-in is free up to 50,000 monthly active users, and Cloud Functions include 2 million calls a month before $0.40 per million.
The things to watch: pay-as-you-go has no ceiling of its own. Firebase's standard budget alerts email you but, in Firebase's own words, "do not pause services"; spending caps exist only for some services. A loop or a query that reads far more than it needs can run up a bill before anyone notices.
What Firebase doesn't give you is the staff portal, the booking calendar or the shop. Those are yours to build, or to pay someone to build, on top of it.
Retool: per person, per month
Retool is a tool for building internal apps (admin panels, dashboards, staff tools) on top of a database you already have. Prices are per user, billed yearly:
| Plan | Builder | Internal user | Notes |
|---|---|---|---|
| Free | $0 | $0 | Up to 5 users. No external users. |
| Team | $10 a month | $5 a month | No external users. |
| Business | $50 a month | $15 a month | External users at tiered prices. |
| Enterprise | Custom pricing. | ||
Retool is quick for staff tools, and the free plan suits a team of up to five. It isn't built for your customers: a public booking page or shop is outside what it's for, and you still need a database behind it.
Self-hosted: pay once, plus a server
Self-hosting means the backend runs on a server you rent or own. With BackendGen.dev you generate the staff portal, records, shop and bookings as source code, then run it yourself:
| Cost | Amount |
|---|---|
| Base licence | $249 once: staff portal, roles, records, backups |
| Advanced licence | $449 once: adds the online shop and online bookings |
| A small server | For example Hetzner's smallest shared server, €5.49 a month plus its IPv4 address |
| Stripe and PayPal | Their usual fees on payments you take (the same with any option) |
Both licences include unlimited projects and free updates for all of 1.x. You can also run it on a computer you already have, for nothing, though a proper server is better for anything your customers rely on.
Worked example: a salon over two years
A salon with six staff who all sign in, a few hundred online bookings a month, and a booking page on its website. Two years of each option:
| Option | Two years | What's still to do |
|---|---|---|
| Firebase | About $0 in Firebase fees: well inside the free allowance | Build the portal, calendar, booking page and emails yourself, or pay a developer to |
| Retool (Team) | 1 builder and 5 staff: $35 a month, $840 | Build the screens; add a database; the customer booking page is still needed elsewhere |
| Self-hosted (Advanced) | $449, plus a small server: about €132 at the price above | Set up the server once and keep it updated |
Over two years the self-hosted option already costs less than Retool's Team plan here (about $600 against $840, before Retool's database), and the gap grows every year: from year three only the server is left to pay. With five people or fewer, Retool's free plan would cost nothing, though the building work and the database remain. Firebase's fees are the lowest, but only because building and maintaining the app isn't counted; that's almost always the biggest cost of all.
What isn't about money
- Where the data lives. Self-hosted, your customers' details stay on a server you choose, in the country you choose, and no one else processes them for you. That makes GDPR simpler, though no software makes you compliant by itself.
- Lock-in. An app built on Firestore's API or in Retool stays there; moving means rebuilding. Self-hosted code and a SQLite database file move to any server.
- Who looks after it. Firebase and Retool run the servers for you. Self-hosted, keeping the server updated and copying backups somewhere safe is your job, or your web developer's.
- Predictable bills. A one-time licence and a fixed-price server don't change with how busy you are.
Which to choose
| Choose | If |
|---|---|
| Firebase | You're building your own app with a developer, want Google to run the servers, and expect to grow fast. |
| Retool | You need quick internal screens over data you already have, and your team is small or the per-user cost doesn't matter. |
| Self-hosted | You want a finished portal, shop or bookings, the data on your own server, and no monthly fees, and someone can look after a small server. |
| A hosted booking or shop service | You want nothing to set up at all, or need payment taken when people book. |
Sources
- Firestore pricing, Google Cloud: reads, writes, deletes and the free daily allowance.
- Firebase pricing: Blaze plan, Authentication and Cloud Functions allowances.
- Set up budget alerts for Firebase services: "Alerts-only budgets do not pause services."
- Retool pricing: plans and per-user prices (yearly billing).
- Hetzner's June 2026 cloud price change: CX23 at €5.49 a month (Germany and Finland).
Prices change: check the providers' own pages before you decide. Spotted something out of date? Email hello@backendgen.dev.
See what you'd get
Set up a staff portal, shop or bookings in the business generator with a free account, and see exactly which files you'd get before you buy.
Open the business generatorBusiness backendsMore for businesses: online bookings for a clinic or salon · a secure staff portal with Node.js and SQLite.