The best BaaS (Backend as a Service, a hosted backend that handles your database, authentication, storage and server functions so you don't build them from scratch) free tiers right now are Supabase and Appwrite Cloud. Both hand you a genuinely usable production backend with no credit card required. Firebase's Spark plan is fine for a prototype, but it pushes you towards the uncapped Blaze plan fast. Convex and Nhost are worth a serious look too. None of this matters as much as what happens the week your app actually gets traffic.
I've watched dozens of founders pick a BaaS off a Reddit thread, build for three months, then panic when the bill arrives. The free tier was never the problem. The problem is the gap between "free" and "the first invoice", and almost nobody checks that gap before they start coding. This is the exact question I see on r/SelfHosting every week: which backend won't screw me when I have zero budget but real users. Let's answer it properly.
What's the best BaaS free tier right now?
For most people building a real app, Supabase and Appwrite Cloud currently offer the most usable free tiers. You get a real relational or document database plus auth and file storage without a card on file. Firebase's Spark plan is generous for prototypes, but the moment you need server-side functions at any volume, you're pushed onto Blaze. Convex and Nhost both deserve a spot on your shortlist depending on what you're building.
There isn't a single universal winner, because each platform optimises its free tier for a different kind of app. A content site with light traffic has completely different needs from a realtime collaborative tool with dozens of concurrent editors. That's why the rest of this article breaks the decision down by app type rather than pretending one answer fits everyone.
What exactly is a BaaS, and why does it matter for startups with no budget?
A BaaS is a hosted backend that gives you a database, user login, file storage and often serverless functions (small pieces of backend code that run on demand instead of on a server you manage) as one package. Instead of provisioning a server, installing Postgres, writing auth from scratch and configuring file storage, you call an SDK (software development kit, a set of tools a vendor gives you to talk to their platform) and it's already there.
For a founder with no money and no time, this is the entire pitch. You skip weeks of backend plumbing and ship a working product in days. The trade-off is that you're now dependent on someone else's pricing decisions, someone else's outages and someone else's definition of "free". That dependency is exactly what this article is here to help you manage.
If you're deciding where the frontend of your app lives too, our guide to free web app hosting covers the other half of the stack. A BaaS handles your data and logic; you still need somewhere to serve your HTML, JS and CSS.
How do Supabase, Firebase, Appwrite, Convex and Nhost free tiers actually compare?
Every one of these platforms changes its free tier limits often, sometimes more than once a year, so treat any number you read anywhere, including here, as a snapshot rather than a permanent fact. The only reliable move is to check the vendor's own pricing page before you commit, because a blog post from six months ago may already be wrong.
What doesn't change as often is the shape of each offer. Supabase gives you a real Postgres database (an open-source relational database, the same engine used by large production systems) with row-level security built in. Firebase gives you Firestore, a NoSQL document database, plus generous auth limits under its Spark plan, as detailed on the Firebase pricing page. Appwrite Cloud gives you a full backend stack, including auth, database, storage and functions, described on the Appwrite pricing page.
Convex takes a different approach entirely, treating your backend as reactive functions and a document store, with its own free allowance listed on the Convex pricing page. Nhost bundles Postgres, auth, storage and serverless functions in one project, with details on the Nhost pricing page. All five are worth reading directly before you build anything on top of them.
| Platform | Database | Auth (MAU) | Storage | Bandwidth / egress | Function invocations | Pauses when inactive | First paid tier |
|---|---|---|---|---|---|---|---|
| Supabase | Postgres, limit changes often, see Supabase pricing | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Yes, free projects pause after inactivity | Supabase Pro, from $25/month |
| Firebase (Spark) | Firestore, limit changes often, see Firebase pricing | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | No pausing, but Cloud Functions require Blaze | Blaze, pay-as-you-go, no fixed cap |
| Appwrite Cloud | Document DB, limit changes often, see Appwrite pricing | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Check current policy on pricing page | Appwrite Pro, paid monthly tier |
| Convex | Document store, limit changes often, see Convex pricing | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Check current policy on pricing page | Convex Professional, paid monthly tier |
| Nhost | Postgres, limit changes often, see Nhost pricing | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Limit changes often, see pricing page | Check current policy on pricing page | Paid tier, see pricing page for current price |
| PocketBase | SQLite (a lightweight, file-based database), no cloud free tier, self-host only | No hosted plan, self-managed on your own VPS | Whatever your VPS disk gives you | Whatever your VPS network allowance gives you | Not applicable, it's a single binary you run yourself | Never, it's not a hosted service | Not applicable, cost is only your VPS |
What happens to PocketBase, since it has no cloud free tier?
PocketBase is not a hosted service at all, so there's no free tier to compare, only the cost of the server you run it on. It's a single self-contained binary written in Go, bundling an SQLite database, auth and file storage, that you install on your own VPS (virtual private server, a slice of a physical server you rent and control).
That makes PocketBase the honest baseline for this whole comparison. Every hosted BaaS free tier is really "we'll run this for you for free until we don't want to any more." PocketBase strips that away and hands you the actual, unromantic cost: a few pounds a month for a small VPS, and you own every setting.
The trade-off is you're now the ops team. Backups, updates, scaling and uptime are entirely your job. For a solo founder testing an idea, that's often fine. For a team that wants to focus purely on features, it's a real cost worth weighing against the convenience of a hosted platform.
Why is the free tier not the real risk?
The free tier is not what kills side projects. The scaling cliff does, that sudden jump in price the moment your usage crosses into the paid tier and keeps climbing. Founders plan for the free limits and never model what month two of real growth actually costs.
I've had clients build an entire MVP (minimum viable product, the smallest version of an app worth shipping) on a free plan, get featured somewhere, and wake up to a bill ten times what they expected. It's rarely because the free tier lied to them. It's because nobody read past the first row of the pricing table.
This is exactly why the comparison you actually need isn't "which free tier is biggest" but "which platform's next step is predictable, and which one lets me leave if the number stops making sense." That second question matters far more once your app has real users.
Where does the first paid tier land for each platform?
Supabase's first paid step is Supabase Pro, from $25 a month, a flat, predictable fee that also removes project pausing and increases most limits at once. Firebase's Spark plan gives way to Blaze, a pay-as-you-go plan with no fixed monthly cap, which is either fine or terrifying depending on how well you understand your own traffic.
Appwrite's step up is Appwrite Pro, a paid monthly tier that keeps the same open API you used for free. Convex's is Convex Professional, again a paid monthly plan sitting above the free allowance. Nhost has its own paid tier too, and because all four of these change their exact figures periodically, the right move is always to check the vendor's own pricing page before you budget against it.
The practical difference that matters isn't the exact dollar figure, it's predictability. A flat monthly fee like Supabase Pro or Appwrite Pro is a number you can put in a spreadsheet. A pay-as-you-go plan like Firebase Blaze is a number you can only guess at until you've already spent it.
Which platforms let you self-host when the bill arrives?
Supabase, Appwrite, PocketBase and Nhost all let you take the same stack and run it yourself on a VPS. That's the single biggest reason I steer people towards them. Firebase and Convex do not offer that exit, though Convex has open-sourced its backend, which gives you the code without a simple hosted-to-self-hosted migration path.
This is the decision that actually protects a broke founder. If Supabase's price ever stops making sense, you export your Postgres database and move it to your own server, following the same approach we cover in our VPS hosting guide. Appwrite and Nhost work the same way, and PocketBase was built for exactly this from day one.
Firebase locks you into Google's infrastructure and Firestore's data model. Moving off it later means a real rewrite, not a config change. Convex's open-source backend is a genuinely good move by that team, but you're still rebuilding your own hosting and ops layer from scratch if you ever leave their cloud.
- Self-host exit available: Supabase, Appwrite, PocketBase, Nhost
- No simple self-host exit: Firebase, Convex (though Convex's backend is open source)
- Where to run it yourself: our VPS hosting picks or browse the full hosting directory
Which BaaS should you pick for your type of app?
Your answer depends entirely on what you're building, not on which free tier looks biggest on a comparison chart. A content-heavy app, a realtime collaborative tool, a mobile app and a side project you might abandon each want a different platform.
For a content app with mostly reads and simple writes, Supabase's Postgres database and generous auth make it the easiest starting point, and its self-host exit means you're never fully locked in. For a realtime collaborative app, such as a shared document or live dashboard, Convex's reactive function model was built specifically for that pattern and handles it more naturally than bolting realtime onto a traditional database.
For a mobile app with auth as the priority, Firebase's maturity, SDK quality and documentation are hard to beat, provided you accept Blaze's pay-as-you-go model once you outgrow Spark. For a side project that might die next month, PocketBase on a cheap VPS costs you almost nothing to keep alive, since there's no vendor bill ticking regardless of whether anyone uses it.
- Content app: Supabase, for the real database and clean self-host path
- Realtime collaborative app: Convex, built around reactive functions
- Mobile app with auth: Firebase, for SDK maturity, with Blaze budgeted for
- Side project that might die: PocketBase on the smallest VPS you can find
Appwrite and Nhost both sit as strong general-purpose alternatives to Supabase if you want a different developer experience or already use GraphQL, which is Nhost's default API style. Check both against our hosting directory alongside whichever cloud hosting setup runs your frontend.
Quick recommendations before you build anything
Start with Supabase or Appwrite if you have no strong preference. Both give you a genuine self-host exit and a flat, predictable first paid tier. Budget for Firebase Blaze from day one if you choose Firebase, rather than discovering pay-as-you-go pricing the hard way after launch. If your project might vanish next month, put PocketBase on the cheapest VPS you can find rather than paying a hosted platform's ongoing tax for an idea that isn't validated yet.
Frequently Asked Questions
Is Supabase or Firebase better for a free tier?
Supabase gives you a real Postgres database and a flat, predictable first paid tier at $25 a month. Firebase's Spark plan is fine for prototypes, but it pushes you onto pay-as-you-go Blaze pricing once you need Cloud Functions at scale, which is harder to budget for.
Does Appwrite Cloud have a genuinely free tier, or is it a trial?
Appwrite Cloud offers an ongoing free tier, not a time-limited trial, covering auth, database, storage and functions. Exact limits change periodically, so check the Appwrite pricing page before building against a specific number.
Convex vs Supabase, which should I choose?
Choose Convex if your app is heavily realtime and collaborative, since its reactive functions were built for that pattern. Choose Supabase if you want a standard relational database, SQL familiarity, and a straightforward path to self-hosting on your own VPS later.
Can I self-host Firebase if the bill gets too high?
No. Firebase is tightly bound to Google's infrastructure and Firestore's proprietary data model, so there's no simple lift-and-shift to your own server. Moving off Firebase later means a genuine rewrite of your data layer, not just a hosting change.
What's the safest BaaS for a side project with zero budget?
PocketBase on a small VPS is the safest choice, because there's no vendor bill regardless of usage, only your fixed server cost. If you'd rather stay fully hosted, Supabase and Appwrite both have usable free tiers with no credit card required.
Do free-tier projects get paused if I stop using them?
Some platforms pause inactive free projects, Supabase among them, so you may need to manually restart a dormant project. Policies change, so check each vendor's current pricing page rather than assuming your project will sit untouched forever.
The bottom line
Every free tier here is good enough to launch on. The decision that actually protects you is which platform lets you leave on your own terms when the bill stops making sense. Pick Supabase or Appwrite by default, keep Convex and Firebase for the specific jobs they're best at, and always know where your VPS exit is before you need it.
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