Auth, a database and hosting from Google, with no payment method listed for the Spark quotas. Firebase is Google's backend platform for web and mobile apps, with authentication, two databases (Cloud Firestore and Realtime Database), file storage, hosting and Cloud Functions. The pricing page lists no-cost allowances on the Spark plan: authentication for up to 50,000 monthly active users, Firestore with 1 GiB stored and 50,000 reads and 20,000 writes a day, Realtime Database with 1 GB stored and 200,000 simultaneous connections, and Hosting with 10 GB stored. The Blaze plan is pay as you go and needs a billing account. G2 reviewers say Firebase removes backend work for small teams, and the same reviewers warn about cost after the free tier and about vendor lock-in. Two Reddit thread titles suggest Cloud Storage and Cloud Functions are not usable on Spark alone, so check that before you plan around them.
Free tier quotas
Plan
Spark, no cost, no payment method listed for the quotas below
Authentication
Up to 50,000 monthly active users, 50 for SAML and OIDC
Cloud Firestore
1 GiB stored, 10 GiB per month egress, 50,000 reads, 20,000 writes and 20,000 deletes per day
Realtime Database
1 GB stored, 200,000 simultaneous connections, 360 MB per day of transfer
Hosting
10 GB stored, 360 MB per day of data transfer
Cloud Storage
5 GB, 10 GB per month, 20,000 uploads and 50,000 downloads per day (see the catch)
Cloud Functions
2M invocations and 400,000 GB-seconds per month (see the catch)
Blaze plan
Pay as you go, billing account required
Last sniffed Oct 20, 2026. Always confirm on the official pricing page.
👍 Good boy
+The pricing page lists authentication free for up to 50,000 monthly active users, and 50 monthly active users for SAML and OIDC sign-in.
+Cloud Firestore has a no-cost allowance of 1 GiB stored and 10 GiB a month of egress, with 50,000 reads and 20,000 writes a day.
+Realtime Database lists 200,000 simultaneous connections and 1 GB stored at no cost, which suits chat and live-state features.
+Hosting lists 10 GB stored and 360 MB a day of transfer at no cost, so a small site can sit next to the backend.
+A Reddit answer in r/Firebase says a project on the Spark plan cannot incur cost, because it is not attached to a billing account.
+A G2 reviewer on a small marine platform said Firebase handles a lot of the work so the team can improve the product instead of managing servers.
+Another G2 reviewer said that for a startup team it removed a lot of backend overhead early on.
👎 Watch out
−A G2 reviewer wrote that Firebase is very expensive once you pass the free tier.
−A G2 reviewer said cost predictability gets harder as usage grows, especially Firestore reads and writes and network egress.
−The same G2 reviewer called vendor lock-in real and said migrating away later can be expensive in engineering time and architecture changes.
−Firestore's free quotas are daily (50,000 reads, 20,000 writes), so one busy day can use them up before the month ends.
−Realtime Database stored data costs $5 a GB on Blaze after the free allowance, per the pricing page extract, which is much higher than Cloud Storage at $0.026 a GB.
−Two r/Firebase thread titles say Firebase Storage is no longer accessible on Spark and ask what Spark is good for without Functions. I read only the titles and short excerpts, so treat them as a warning to check, not a ruling.
The catch
The pricing page I read lists a no-cost allowance for Cloud Storage and Cloud Functions next to the Spark quotas, but I could not tell from the extracted text whether those two products work on Spark without a billing account. Two r/Firebase thread titles point the other way ("Firebase Storage no longer accessible under Spark Plan" and a question about using Firebase without Functions on Spark). Open the Firebase console for a new project and check before you design around either product.
The Blaze plan is usage based with no monthly fee and needs a billing account. The page extract lists Realtime Database at $5 per GB after the free allowance, Cloud Storage at $0.026 per GB, Cloud Functions at $0.40 per million invocations, and says Phone Number Verification is billed per SMS. The extract also mixed in a line for Authentication pricing that did not look right, so I left it out.
Firestore quotas are daily. A G2 reviewer's complaint about cost after the free tier and about lock-in is a single review, not a pattern I could count, but it matches what the pricing structure suggests: reads, writes and egress are all metered.
What’s included
✓Authentication
✓Cloud Firestore
✓Realtime Database
✓Cloud Storage
✓Hosting
✓Cloud Functions
✓SAML and OIDC sign-in
✓Phone number verification
✓Pay-as-you-go Blaze plan
Free tier value
Generosity
B
Estimated value
Auth for 50K users, Firestore and Realtime Database
Feature parity
Auth for 50K users, Firestore and Realtime Database free. Storage and Functions may need Blaze.
Screenshots
Firebase homepageFirebase pricing page
Paid plans
Blaze, pay as you go
Needs a billing account. No monthly fee. The extract lists Realtime Database at $5 per GB after the free allowance, Cloud Storage at $0.026 per GB, Cloud Functions at $0.40 per million invocations and $0.003 per minute, and Phone Number Verification billed per SMS.
Spark, no cost
The plan with the allowances listed above. A Reddit answer says a project on Spark is not attached to a billing account, so it cannot charge you.
Common questions
Is Firebase free?
Yes, the Spark plan has no cost. It lists authentication for up to 50,000 monthly active users, Firestore with 1 GiB stored, Realtime Database with 1 GB stored and Hosting with 10 GB stored.
Do I need a credit card?
The pricing page marks the Spark allowances as needing no payment method, and a Reddit answer says Spark projects have no billing account. Blaze needs a billing account.
Can Spark charge me by surprise?
A Reddit answer in r/Firebase says no, because a Spark project is not associated with a billing account. Moving to Blaze changes that.
Do Cloud Storage and Cloud Functions work on Spark?
I could not confirm. The pricing page lists free quotas for them, but two Reddit thread titles suggest they need Blaze. Check a new project in the console.
What do reviewers complain about?
G2 reviewers mention cost after the free tier, cost predictability with Firestore reads, writes and egress, and vendor lock-in that makes migration expensive.
Who is it for?
G2 reviewers describe small and startup teams that want to avoid running backend servers early on.
Change history
Checked October 22, 2026
The pricing page lists Spark quotas for authentication, Firestore, Realtime Database, Cloud Storage, Cloud Functions and Hosting, and Blaze pay-as-you-go rates.
