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Firebase pricing for a mobile app: Spark vs Blaze costs

Firebase's Spark plan is free, and many small apps never pay. In our 100,000-user example, Blaze costs about $46 a month, mostly Firestore reads.

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Firebase costs nothing to start: the Spark plan needs no payment method and includes 50,000 Firestore document reads and 20,000 writes a day, 1 GiB of database storage, and free push notifications, sign-in, analytics and crash reports. You pay only on the Blaze plan, and only for use above those allowances. In the example below, an app with 1,000 monthly users pays $0, one with 10,000 pays about $3 a month, and one with 100,000 pays about $46, as of October 2026.

Those bills depend on assumptions about usage, set out in the examples. The prices come from Firebase’s pricing page, the Firebase and Google Cloud pricing docs, and Google Cloud’s Identity Platform price list, all read on October 31, 2026. We haven’t run an app on Firebase ourselves; we’ve done the arithmetic from Google’s published rates. Prices are in US dollars before tax.

What are Firebase’s two plans?

Firebase has two pricing plans, and every project is on one of them:

  • Spark (no cost). Google says it has “generous no-cost usage limits” and “no payment method needed.” You can use it for a live app; Firebase’s plan docs say you “can use the Spark pricing plan in production apps.”
  • Blaze (pay as you go). You link a Google Cloud Billing account. You get the same no-cost allowances as Spark, then pay for use above them, and you get access to products Spark doesn’t include, such as Cloud Functions. Google says eligible new Blaze users “get $300 in free credit.”

The catch on Spark: Firebase’s plan docs say that if you go over a no-cost limit, “your project’s usage of that specific product will be shut off for the remainder of that month,” for every app in the project, unless you upgrade. On Blaze, the app keeps running and you’re billed for the extra.

What does the free Spark plan include?

Some Firebase products cost nothing on either plan, at any size. Firebase lists these as no-cost: A/B Testing, Analytics, App Check, App Distribution, Cloud Messaging (FCM), Crashlytics, In-App Messaging and Performance Monitoring. Push notifications through Cloud Messaging are free, which matters for most mobile apps.

The paid products have these allowances on Spark (and the same or more on Blaze):

Product Spark no-cost allowance Blaze price after the allowance
Firestore: document reads 50,000 a day $0.03 per 100,000
Firestore: document writes 20,000 a day $0.09 per 100,000
Firestore: document deletes 20,000 a day $0.01 per 100,000
Firestore: stored data 1 GiB $0.15 per GiB-month (see note)
Firestore: network egress 10 GiB a month Google Cloud pricing
Authentication (email, social, anonymous) Included Included
Authentication with Identity Platform 50,000 monthly active users From $0.0055 per user (see below)
Phone sign-in (SMS) Not available Per SMS sent, by country
Hosting: storage 10 GB $0.026 per GB
Hosting: data transfer 360 MB a day $0.15 per GB
Realtime Database: storage 1 GB $5 per GB
Realtime Database: downloads 10 GB a month $1 per GB
Realtime Database: connections 100 200,000 per database
Cloud Functions Not available 2M invocations a month free, then $0.40 per million
Cloud Storage (default bucket) Not available 5 GB-months stored and 100 GB a month downloaded free, then Cloud Storage pricing
Remote Config fetches 100,000 a day $0.06 per 10,000 (from September 1, 2026)

Firestore rates are for the Standard edition in the Iowa (us-central1) location, the one Google’s price table shows by default; other locations are priced differently. Google’s table lists stored data at $0.000205479 per GiB in its default hourly view; over a 730-hour month that’s $0.15 per GiB. Firestore’s docs say quotas “are applied daily and reset around midnight Pacific time,” and that only one database per project gets the free quota.

The Cloud Storage free allowance applies only to buckets in us-central1, us-west1 and us-east1, according to the pricing page. Older default buckets on *.appspot.com have their own rates: 5 GB free, then $0.026 per GB stored, and 1 GB a day of downloads free, then $0.12 per GB.

How much does Firebase cost per month? Three example apps

Here’s what Blaze would cost for one app at three sizes. The assumptions are ours, not Google’s, and real apps vary a lot. Change the reads per user and the bill changes with it.

Assumptions: a 30-day month; 30% of monthly users open the app on a given day; each of those users causes 100 Firestore document reads and 10 writes a day; about 20 KB of data stored per user; sign-in by email or Google (no SMS); push notifications through Cloud Messaging; 5 Remote Config fetches per daily user. Firestore in us-central1 at the default rates.

1,000 monthly users 10,000 monthly users 100,000 monthly users
Daily users 300 3,000 30,000
Reads per day 30,000 300,000 3,000,000
Writes per day 3,000 30,000 300,000
Stored data 0.2 GiB 2 GiB 20 GiB
Remote Config fetches per day 1,500 15,000 150,000

1,000 monthly users: $0. 30,000 reads and 3,000 writes a day are under the 50,000 and 20,000 daily allowances, and 0.2 GiB is under the 1 GiB storage allowance. This app fits on Spark.

10,000 monthly users: about $2.67 a month on Blaze.

  • Reads: 300,000 − 50,000 free = 250,000 a day. × 30 days = 7.5 million. 7.5M ÷ 100,000 = 75 × $0.03 = $2.25
  • Writes: 30,000 − 20,000 free = 10,000 a day. × 30 = 300,000. 3 × $0.09 = $0.27
  • Storage: 2 GiB − 1 GiB free = 1 GiB × $0.15 = $0.15
  • Remote Config: 15,000 a day is under the 100,000 allowance: $0
  • Total: $2.25 + $0.27 + $0.15 = $2.67

On Spark, this app would go over the 50,000 daily read allowance on its first day, and Firestore would stop working for the rest of the period. That’s why apps of this size need Blaze even though the bill is small.

100,000 monthly users: about $45.96 a month on Blaze.

  • Reads: 3,000,000 − 50,000 = 2,950,000 a day. × 30 = 88.5 million. 885 × $0.03 = $26.55
  • Writes: 300,000 − 20,000 = 280,000 a day. × 30 = 8.4 million. 84 × $0.09 = $7.56
  • Storage: 20 − 1 = 19 GiB × $0.15 = $2.85
  • Remote Config: 150,000 − 100,000 = 50,000 a day. × 30 = 1.5 million. 150 × $0.06 = $9.00
  • Total: $26.55 + $7.56 + $2.85 + $9.00 = $45.96

Doubling the reads per user to 200 would add roughly another $27 a month at this size. Reads are the line to watch.

What’s not included: Firestore network egress beyond 10 GiB a month, Cloud Storage for photos or files, Cloud Functions, and SMS. Google prices egress and Cloud Storage on its Cloud price lists rather than on the Firebase page, so we haven’t estimated them.

How much does Firebase Authentication cost?

For most apps, nothing. Firebase’s pricing page lists “other Authentication services” as included on both plans, and its plan docs give the example of an app using social sign-in that pays nothing “even if your app has several million users.”

Two things do cost money:

Phone sign-in by SMS. It isn’t available on Spark. On Blaze, Google bills per SMS sent, and “the first ten SMS that you send per day are not billed.” Google’s price list shows $0.01 per SMS to the United States and Canada and $0.04 to the United Kingdom, with other countries priced individually.

Worked example: 2,000 US sign-in texts in a 30-day month. The first 10 a day are free: 10 × 30 = 300. 2,000 − 300 = 1,700 × $0.01 = $17.00.

Upgrading to Firebase Authentication with Identity Platform. This upgrade adds features such as SAML and OpenID Connect sign-in, and it switches billing to monthly active users. Google’s Identity Platform prices for email, phone, anonymous and social sign-in:

Monthly active users Price per user per month
First 50,000 $0
50,000 to 100,000 $0.0055
100,000 to 1 million $0.0046
1 million to 10 million $0.0032
Over 10 million $0.0025

SAML and OpenID Connect users are free up to 50 a month, then $0.015 each. Google counts “any account that has signed in within a given month” as active.

Worked example: the 100,000-user app above on Identity Platform pays 50,000 × $0.0055 = $275 a month for sign-in alone, six times its Firestore bill. Unless you need what Identity Platform adds, staying on standard Firebase Authentication keeps that at $0.

What else on Firebase costs money?

  • Cloud Functions (Blaze only): 2 million invocations, 400,000 GB-seconds and 200,000 CPU-seconds a month free, then $0.40 per million invocations and Google Cloud rates for compute. Outbound networking is free up to 5 GB a month, then $0.12 per GB. Cloud Build minutes, used when you deploy functions, are free up to 120 a day, then $0.003 a minute.
  • App Hosting (Blaze only): outgoing bandwidth free up to 10 GiB a month, then $0.20 per GiB uncached or $0.15 cached; storage free up to 5 GB, then $0.10 per GB. Cloud Run and other Google Cloud products it uses are billed at their own rates.
  • Test Lab: 10 virtual-device tests a day on Spark; on Blaze, 60 minutes a day of virtual devices free, then $1 per device per hour, and 30 minutes a day of physical devices free, then $5 per device per hour.
  • SQL Connect (PostgreSQL): a 3-month no-cost trial of one Cloud SQL instance, then “starting as low as $9.37 / month,” according to the pricing page. If you don’t upgrade to Blaze before the trial ends, Google archives the instance and deletes it after another 90 days.
  • Firebase AI Logic: billed at Google Cloud or Gemini Developer API rates.
  • Firestore discounts: Google lists 1-year and 3-year committed-use prices of $0.024 and $0.018 per 100,000 reads, and $0.072 and $0.054 per 100,000 writes, against $0.03 and $0.09 on demand.

What about Firebase Studio?

People searching for Firebase pricing often ask whether Firebase Studio is free. The pricing page says Firebase Studio is “no-cost for three workspaces,” and that Google Developer Program members get 10 workspaces on the no-cost Standard tier or 30 on Premium, with a larger Gemini quota for the App Prototyping agent. Some integrations, such as App Hosting, need a billing account.

What to watch for

  • Budget alerts don’t stop spending. Firebase’s docs say “budget alerts do not cap your usage or charges.” Set them anyway, and for AI Logic, App Hosting, Cloud Functions and Extensions, Google “strongly” recommends also setting spend caps, which pause new use of that service when it hits its budget.
  • Linking a billing account upgrades you. Firebase says linking a Cloud Billing account, including one with the $300 trial credit, automatically moves the project to Blaze.
  • Spark shuts off, it doesn’t bill. Go over a Spark limit and that product stops for the rest of the period for every app in the project.
  • Reads add up through queries. Firestore charges for documents returned and for index entries read: “one read operation for each batch of up to 1000 index entries.” Listening for live updates on large collections multiplies reads.
  • Only one free database. The first Firestore database in a project gets the free quota. Extra named databases are billed from the first read.
  • Location changes the price. All Firestore rates here are for us-central1.
  • Remote Config now has a price. From September 1, 2026, fetches over 100,000 a day per project cost $0.06 per 10,000, and $0.01 per 10,000 above 10 million a day.

Is Firebase cheaper than Supabase?

It depends on your usage, because the two price differently. Supabase charges a flat plan price; Firebase charges per operation. From our data on Supabase (checked October 25, 2026): the free plan gives 2 active projects, a 500 MB database, 1 GB of file storage, 5 GB of egress and 50,000 monthly active users, and the paid plan starts at $25 a month. Supabase pauses free projects after a week without activity.

For the example apps above, Firebase on Blaze costs $0, $2.67 and $45.96 a month. A 10,000-user app on Firebase pays less than Supabase’s $25 entry price, as long as reads per user stay modest. A read-heavy app at 100,000 users can pass it. Run your own numbers with your expected reads per user before you pick.

Which plan should you choose?

  • You’re building or testing an app: Spark. It costs nothing, needs no card and can’t surprise you with a bill.
  • Your app is live with a few hundred daily users: Spark may still be enough, as long as reads stay under 50,000 a day. Watch the usage dashboard.
  • You need Cloud Functions, phone sign-in, Cloud Storage for uploads, or reads above 50,000 a day: Blaze. Set a budget alert the same day, and spend caps on Functions.
  • You need SAML or OIDC sign-in for business customers: Identity Platform, priced per active user over 50,000 (or over 50 for SAML/OIDC users).
  • You’re choosing a backend for a no-code app: many builders connect to Firebase directly. See what it costs to make an app, our Android app builder comparison and the Android app builders hub. For other free tiers, see our free tools list.

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