Checked September 26, 2026. USD, excluding tax. Based on published pricing pages, not a hands-on load test. Jet Admin publishes this comparison and competes with neither product.
Most Supabase vs Firebase comparisons open with SQL versus NoSQL. That's a real difference, but it's rarely the one that bites. The one that bites is billing: Supabase sells you a plan with a spend cap turned on by default; Firebase's paid plan is metered Google Cloud consumption with no plan tier at all.
If you have ever been surprised by a cloud bill, that sentence is the comparison.
At a glance
| Supabase | Firebase | |
|---|---|---|
| Free plan | Free — $0/month | Spark — free, no payment method required |
| Paid entry | Pro — $25/month | Blaze — pay-as-you-go, no fixed fee |
| Higher tier | Team — $599/month | None — Blaze scales by usage |
| Enterprise | Custom | Google Cloud terms |
| Database model | Postgres (relational, SQL) | Firestore (document, NoSQL) |
| Spend control | "Spend caps are on by default on the Pro Plan" | Budget alerts; charges accrue daily at Google Cloud rates |
| Signup credit | — | "$300 if eligible" |
Sources: Supabase pricing and Firebase pricing, checked September 26, 2026.
What each free tier actually gives you
Supabase Free includes a 500 MB database on shared CPU with 500 MB RAM, 1 GB file storage, 5 GB egress, 50,000 monthly active users and 500,000 Edge Function invocations. The 50,000 MAU figure is unusually generous for a free tier — many apps will hit the 500 MB database ceiling long before the user ceiling.
Firebase Spark is free with no payment method required, and its quotas are expressed per day rather than per month: 1 GiB of stored Firestore data, 50,000 reads a day, 20,000 writes a day, 20,000 deletes a day, and 10 GiB of network egress a month.
Those daily quotas are the thing to model. 50,000 reads a day sounds ample until you build a dashboard that re-reads a collection on every page load. Firestore bills per document read, so an inefficient query pattern is a cost pattern, not just a performance one.
Where the money actually differs
Supabase Pro at $25 includes 8 GB of database disk, 100 GB file storage, 250 GB egress, 100,000 MAU, 2 million Edge Function invocations, and $10/month in compute credits — which covers one Micro instance at $10/month. Beyond those allowances the published overage rates are $0.125 per GB of database, $0.09 per GB of egress, $0.0213 per GB of storage and $0.00325 per MAU.
Firebase Blaze has no plan fee. You keep the Spark free quotas and pay Google Cloud rates for everything above them, calculated daily. There's a $300 credit if you're eligible.
This produces a genuine crossover. For a small app that stays inside the free quotas, Blaze can cost literally nothing while Supabase Pro costs $25 — Supabase's free tier is the fair comparison there. For an app with steady, predictable load, Supabase's $25 buys allowances that would cost more metered. For an app with spiky or read-heavy traffic, Blaze's per-unit billing can run well above $25 in a bad month.
The spend cap is the real differentiator
Supabase turns spend caps on by default on Pro. Exceed your allowances with the cap on and you hit a limit rather than a bill; you have to actively toggle it off to enable pay-as-you-grow.
Firebase has no equivalent default. Budget alerts tell you what has already happened. The well-documented failure mode across metered cloud services — a runaway loop, a misconfigured client, a viral moment — produces a bill rather than a ceiling.
Which behaviour you want is a genuine judgement call, not a flaw in either product. A ceiling that stops your app during a traffic spike is its own kind of bad day. But the default matters: one platform makes you opt into unbounded spending, the other makes you opt out of it.
SQL versus NoSQL, briefly
Supabase is Postgres. You get relational modelling, joins, constraints, transactions, and the ability to hire someone who already knows it. You also get row-level security as the authorization primitive, which is powerful and easy to get subtly wrong.
Firestore is a document store. It scales horizontally without you thinking about it and suits denormalized, read-optimized data. It makes relational queries awkward, and the cost model rewards data shapes you may not want to design around.
The honest heuristic: if your data has genuine relationships and your team knows SQL, Postgres will fight you less. If your access patterns are simple key-based reads at large scale, Firestore's model is a fit rather than a compromise.
Which should you choose?
Choose Supabase if you want relational data, a predictable monthly bill, a spend cap by default, or the option to self-host and leave. Its free tier is also the more generous of the two for user count.
Choose Firebase if you're already in Google Cloud, if your app is genuinely read-simple at scale, or if you want to pay nothing at all while usage stays inside the daily quotas. The maturity of its client SDKs and its mobile story remain real advantages.
Estimate before committing either way. For Firebase, count document reads per user session and multiply by your expected sessions — that single number tells you more than any tier table. For Supabase, check your database size against the 8 GB Pro disk first.
Where Jet Admin fits
Neither is an alternative to Jet Admin; they're often what sits underneath it. Both are backends you build an application on top of, and you still write that application.
Jet Admin connects to a database or API you already have — including a Supabase Postgres instance — and gives you the interface layer without building it. If what you need on top of your backend is an admin panel, a support queue or an internal dashboard rather than a customer-facing app, that's the overlap. For the customer-facing app itself, you still need one of these underneath.
Frequently asked questions
Which is cheaper?
Depends entirely on shape. Inside the free quotas Firebase Blaze can be $0 against Supabase Pro's $25. With steady predictable load, Supabase's included allowances usually win. With spiky read-heavy traffic, Blaze can exceed $25 substantially.
Does Supabase have a free tier?
Yes — $0/month with a 500 MB database, 1 GB storage, 5 GB egress, 50,000 monthly active users and 500,000 Edge Function invocations.
Can I get a surprise bill from either?
From Firebase, yes — Blaze bills consumption daily with no default cap. From Supabase Pro it's much harder, because spend caps are on by default and you must actively disable them.
Is Supabase really open source?
Supabase can be self-hosted, which gives you an exit path that Firebase does not offer. Whether you'd want to operate it yourself is a separate question — the option mainly matters as leverage and as insurance.
What does Supabase Team at $599 add?
Its published resource allowances match Pro — 8 GB disk, 100 GB storage, 250 GB egress, 100,000 MAU. You're buying organizational and compliance capability, not more capacity. Check the feature list against your actual requirements before assuming the jump is warranted.
Can I use both?
Technically yes, and some teams do — Firebase for auth and push, Postgres for relational data. It doubles your operational surface, so have a specific reason.
Model your reads before you pick
Open a spreadsheet and estimate one number: document reads per user session on Firestore, or database size and MAU on Supabase. One of those two numbers will dominate your bill, and knowing which tells you which platform you're actually choosing between.
If the thing you're about to build on top is an internal tool rather than a product, connect Jet Admin to the database directly and skip the application layer entirely.
