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Supabase vs Firebase Free Tier in 2026: Limits, Pausing and When You Start Paying

Supabase Free gives you 500 MB of Postgres and pauses idle projects. Firebase's Spark plan caps differently. Limits side by side, and when each bills.

By Engineer Foodie Desk Oct 24, 2026 ✓ Sources checked Oct 24, 2026

5 min read

Supabase checked Oct 23, 2026 and Firebase checked Oct 24, 2026, on each company’s official pricing pages and docs, linked under Sources. No affiliate links on this page (how we work).

On the Supabase vs Firebase free tier question: pick Supabase Free if you want a real Postgres database (500 MB) plus auth, storage and edge functions in one free project, and pick Firebase’s Spark plan if you want Firestore and hosting with no payment method and no inactivity pause that Google publishes. The catch on each side: Supabase pauses free projects “after 1 week of inactivity”, and Spark leaves out Cloud Functions and Cloud Storage entirely.

We haven’t built the same app on both; everything below is from each company’s own pages.

The short answer

SQL, relational data, want functions on the free plan: Supabase Free.
Mobile-first, document data, app that may sit idle for weeks: Firebase Spark.

Free tiers side by side

Limit	Supabase	Firebase
Database	500 MB Postgres	Firestore: 1 GiB stored
Auth users	50,000 MAU	50K MAU
File storage	1 GB (50 MB max file)	Not on Spark
Egress	5 GB	Firestore 10 GiB/mo; Hosting 360 MB/day
Functions	500K invocations	Not on Spark
Pausing	After 1 week idle	Not published
Projects	2 active	Not published
Card needed	Not charged on Free	“No payment method needed”

Both give you 50,000 monthly active users for auth. Corporate needs you to find the difference between these two pictures. They’re the same picture. Everything else is different.

Supabase Free: what you get and the catches

Per Supabase pricing (Oct 23, 2026), Free includes 500 MB of database, 50,000 monthly active users, 1 GB of file storage with a 50 MB max upload, 5 GB of egress, 500,000 Edge Function invocations, and Realtime with 200 concurrent connections and 2 million messages. You get 2 active projects.

The catches:

Pausing: free projects are “paused after 1 week of inactivity”.
No backups on Free.
Auth emails: the built-in email service allows 2 emails an hour (Supabase auth rate limits, Oct 23, 2026). Real signups need your own SMTP (custom SMTP docs).

Full breakdown: Supabase free tier limits.

Firebase Spark: what you get and the catches

Per Firebase pricing (Oct 24, 2026), Spark needs “No payment method”. You get:

Cloud Firestore: 1 GiB stored, 10 GiB a month of egress, 50,000 reads, 20,000 writes and 20,000 deletes a day.
Authentication: 50,000 monthly active users (50 for SAML/OIDC). Phone auth isn’t available on Spark.
Hosting: 10 GB stored and 360 MB a day of transfer.
Realtime Database: 100 simultaneous connections, 1 GB stored, 10 GB a month downloaded.

The catches:

No Cloud Functions on Spark. Listed as “Not applicable”.
No Cloud Storage on Spark either. File uploads need Blaze.
Daily quotas: Firestore reads are counted per day.
Inactivity pausing: Firebase doesn’t publish an idle-project pause for Spark on these pages. Not published isn’t the same as never.

What happens when you go over

Supabase: you get notified first, then restrictions can follow, including pausing, read-only mode, disabled launches or 402 errors (Supabase billing FAQ, Oct 23, 2026). The cost-control docs say “you will not be charged while using the Free Plan”.

Firebase: Google’s pricing plans doc (Oct 24, 2026) says if you exceed a no-cost quota in a calendar month, “your project’s usage of that specific product will be shut off for the remainder of that month”. You can “wait until the next billing cycle or upgrade to the Blaze pricing plan.” Gandalf energy: you shall not pass, until the 1st.

Neither bills you on the free plan. Both stop you instead.

The first paid step

Supabase Pro is “from $25/month” and includes $10 of compute credits. It raises you to 100,000 MAU, 8 GB of disk, 250 GB of egress and 100 GB of storage, projects are never paused, and a spend cap is on by default (Supabase pricing, Oct 23, 2026). Team starts at $599 a month. Compare it with Neon pricing or follow it on our Supabase pricing tracker.

Firebase Blaze is pay as you go, with Spark’s no-cost usage included. Cloud Functions get 2 million invocations a month free, then $0.40 per million. Cloud Storage on the default buckets includes 5 GB-months stored and 100 GB a month downloaded, in us-central1, us-west1 or us-east1 only. Google says “If eligible, get $300 in free credit”. Two warnings from its own docs: a Cloud Billing account requires a payment method, and budget alerts “do not cap your usage or charges”. Google recommends spend caps for some products, including Functions.

Supabase: a $25 floor with a spend cap. Firebase: no floor, no default ceiling.

Here’s what I’d do

Building something relational, with joins? Start on Supabase Free, set up your own SMTP before launch, and expect the one-week pause until you move to Pro. Building a mobile app that might sit quiet for a while and doesn’t need server functions yet? Spark is the calmer free plan, but watch the daily Firestore read count. If you need functions or file uploads on Firebase, you’re on Blaze from day one, so set a budget alert and know that it won’t stop the bill.

Frontend elsewhere? See Vercel vs Netlify or Cloudflare Workers vs Vercel. Building with an AI app builder? See AI coding tools compared.

FAQ

Is the Supabase free tier better than Firebase’s? It depends on the project, since Supabase Free includes functions and file storage while Firebase Spark has neither but publishes no inactivity pause.

Does Supabase pause free projects? Yes, Supabase says free projects are paused after 1 week of inactivity, and Pro projects are never paused.

Does Firebase need a credit card? Not on Spark, which needs “No payment method”, but Blaze needs a Cloud Billing account, which requires a payment method.

Which is cheaper at scale? Neither page answers that directly: Supabase Pro starts at $25 a month plus usage, while Firebase Blaze bills per use, so price your own traffic on both.

Can I move from Firebase to Supabase? Neither pricing page covers migration, and moving from Firestore documents to Postgres tables is a data-model change, so plan it as a rewrite of your data layer.

Sources

Supabase pricing: https://supabase.com/pricing (checked 2026-10-23)
Supabase billing FAQ: https://supabase.com/docs/guides/platform/billing-faq (checked 2026-10-23)
Supabase cost control: https://supabase.com/docs/guides/platform/cost-control (checked 2026-10-23)
Supabase auth rate limits: https://supabase.com/docs/guides/auth/rate-limits (checked 2026-10-23)
Supabase custom SMTP: https://supabase.com/docs/guides/auth/auth-smtp (checked 2026-10-23)
Firebase pricing: https://firebase.google.com/pricing (checked 2026-10-24)
Firebase pricing plans doc: https://firebase.google.com/docs/projects/billing/firebase-pricing-plans (checked 2026-10-24)