Firebase alternatives, sorted by what you are actually replacing
Firebase alternatives compared by what they actually replace - the database, the auth layer, or the SaaS layer Firebase never had in the first place.
In short
Supabase replaces Firestore with Postgres; Appwrite replaces it with a self-hostable document store. Neither adds subscription billing or workspace RBAC, because Firebase never had those either. If that is the gap, the shortlist is different: BuildBase bundles billing and per-workspace roles alongside auth in one SDK.
Most "Firebase alternatives" lists sort by database. Document store or Postgres, managed or self-hosted, and then a feature grid comparing reads and writes. That sorts for the wrong question if the reason you are looking is not Firestore at all - it is that Firebase never shipped a billing product, never modeled a workspace, and never had a concept of a role.
The one-paragraph answer
If you are leaving Firebase because you want a relational database, self-hosting, or a more open license, Supabase and Appwrite are the honest picks - both replace Firestore and Firebase Auth directly, one managed on Postgres and one self-hostable end to end.
But if the client SDK reach or realtime sync was never the point, and what you actually needed was subscription billing, per-workspace roles and a workflow engine wired to the same auth, that is a different shortlist - and it is one Supabase and Appwrite do not answer either. They replace the database, not the SaaS layer sitting above it. BuildBase belongs on that second list, not as a Firebase clone but as a narrower, more opinionated bet: 20 modules including billing and RBAC, in one SDK, against a data model that already knows what a workspace is.
What Firebase actually leaves you to build
Firebase is Google's mobile and web backend: Firestore for data, Firebase Auth for identity, Cloud Functions for logic, Hosting for static assets, with Crashlytics, Analytics and Remote Config bundled in. Every one of the alternatives below inherits the same shape of gap, because none of them are SaaS platforms either - they are backend-as-a-service, the same category Firebase invented. Firestore has no concept of a subscription plan or a workspace member. You model both yourself, in security rules and Cloud Functions, and you keep that logic in sync by hand every time the product changes. See Firebase vs BuildBase for the full breakdown of what that costs against a bundled SDK, feature by feature.
Where each alternative fits
Supabase - the direct Firestore-and-Auth swap. Supabase pairs a real Postgres database with its own auth service, storage and realtime layer, on a free tier plus paid plans that scale with monthly active users and compute. If the appeal of leaving Firebase is a relational database you can query with SQL instead of security-rule gymnastics, or infrastructure you can eventually self-host, this is the closest like-for-like swap on this list. It still has no native subscription billing or workspace RBAC - see Supabase vs BuildBase for the pricing detail and where that gap shows up in practice. Leaving Supabase itself rather than Firebase? The Supabase alternatives roundup covers the same ground - Firebase, Appwrite, Nhost and PocketBase - from the other direction.
Appwrite - open source, self-hosted from day one. Appwrite covers the same ground as Firestore and Firebase Auth - database, auth, storage, functions - and its managed cloud runs the same software you would run on your own servers. That is a direct answer to the complaint Firebase itself invites: if you are worried about being tied to one vendor's pricing and roadmap, self-hosting the exact stack you would otherwise pay for removes the question entirely. A free tier covers early usage before any paid plan is needed. The tradeoff is that RBAC and billing are exactly as absent here as they are in Firebase - Appwrite gives you the primitives to build them, not the feature itself.
Nhost - Postgres plus GraphQL, if that is the stack. Nhost bundles a managed Postgres database behind Hasura's GraphQL layer, with auth, storage and serverless functions alongside it. It is a narrower bet than Supabase - you are opting into GraphQL as the query interface rather than choosing it later - but for a team that already wants Hasura, it collapses "database plus GraphQL API plus auth" into one bill instead of three.
BuildBase - when the SaaS layer was the actual gap. If none of the above solves the real problem - a paying customer needs a workspace, a workspace needs members, a member needs a role, and a plan change needs to update all three at once - that is the layer none of these tools sell, ourselves included in the "database" sense, since we are not one. BuildBase bundles subscription billing and credit metering, workspaces with RBAC, workflow automation and eight user-facing auth methods (email/password, Google, LinkedIn, GitHub, Microsoft, magic link, passkeys, OAuth 2.0) plus API tokens for server-to-server calls, into @buildbase/sdk.
Launch starts at $49/mo for 25,000 MAU, 1,000 workspaces and 10GB storage; Grow and Scale raise every one of those ceilings. There is no free plan, but the 7-day trial does not ask for a card. Current numbers live at /pricing.
| Feature | BuildBase | Firebase |
|---|---|---|
| Database | Not a product feature - bring your own | Firestore, document store with realtime listeners |
| Subscription billing | Built in, credit metering included | Not provided - wired to your own Stripe account |
| Workspace RBAC | Built in, roles and permissions per workspace | Not a feature - modeled in Firestore security rules |
| Self-hostable | Proprietary SaaS, self-hosted deployment available | Not currently - Google-managed only |
| Mobile / native client SDKs | Web-focused: Next.js, Vite, React Router / Remix, TanStack Start, Express, NestJS, Fastify, Hono, Astro | iOS, Android, Flutter, Unity, Web |
| Realtime data sync | Not a product feature | Firestore realtime listeners with offline support |
Where Firebase wins
Two things Firebase does better than every alternative on this page, BuildBase included, and neither is small. Its client SDKs cover iOS, Android, Flutter and Unity on top of the web - if you are shipping a mobile app or a game, that platform reach is not something a Postgres swap or a bundled SaaS SDK replicates. And Firestore's realtime listeners handle conflict resolution and reconnect-sync automatically, which is the part of offline-first software most teams get wrong on a first attempt. If your product's core value is mobile reach or live collaborative data, stay on Firebase - this post is about what to reach for once that is no longer the deciding factor.
How to actually decide
Match the alternative to the gap you actually hit, not the one every roundup assumes. If it is the database - you want SQL, or you want the option to self-host - Supabase or Appwrite replace Firestore directly, and the choice between them is managed-Postgres versus fully self-hosted from day one. Want GraphQL specifically? Nhost is worth a look before the other two. And if the real gap was never the database at all - if it was that a paying customer needed a workspace, a role and a subscription that stayed in sync, and Firebase was never going to give you any of the three - that is the question Firebase vs BuildBase and the real cost of stitching a stack together yourself answer in more detail than a roundup like this one can.
Exact dollar figures for Firebase and Supabase are deliberately left out of the body above - re-check them in the full Firebase comparison (verified 15 August 2026) and Supabase vs BuildBase (verified 14 August 2026), each checked against the vendor's own pricing page. Appwrite and Nhost pricing is described only in shape here for the same reason: both pages were re-checked on 24 September 2026 and each runs a free tier with paid plans (Nhost's Pro is $25/mo; Appwrite's pricing page did not state its Pro price), but the allowances that decide the bill differ enough between them that appwrite.io/pricing and nhost.io/pricing are worth reading directly before budgeting either. Firestore's per-operation rate is not on Firebase's own pricing page even in the linked comparison, since it defers to region-priced Google Cloud billing.