Firebase Pricing 2026: Where the Free Plan Ends and What It Costs

Firebase pricing 2026: Spark vs Blaze limits, Firestore and phone auth prices, and worked monthly costs for 1k, 10k and 100k users.

The short answer

Firebase is free to start and cheap to run until your usage, not your user count, grows. On the no-cost Spark plan you get 50,000 Firestore reads and 20,000 writes a day, 1 GiB of stored data and 50,000 monthly active users (MAU) of sign-in, with no card needed. The moment you need Cloud Functions you must move to the pay-as-you-go Blaze plan, where the same free quotas still apply. In our worked estimates a Firestore-based app costs about $0 a month at 1,000 MAU, about $2 at 10,000 and about $320 at 100,000, provided you avoid the three bill shocks below. Prices are in US dollars, as Google publishes them.

Sources, last checked 13 October 2026: Firebase pricing, Google Cloud, Firestore pricing (Standard edition, us-central1 rates; London and other regions differ), Google Cloud, Identity Platform pricing. The Firestore storage rate is Google's hourly rate of $0.000205479 per GiB multiplied by about 730 hours in a month.

The rest of this guide explains what Spark and Blaze allow, shows the arithmetic for three app sizes, and covers the bills that surprise founders. Published prices change, so check the sources before you commit a budget.

Spark vs Blaze: what changes when you upgrade

Firebase has two pricing plans, and both apply to the whole project, not to individual apps inside it (Firebase, pricing plans).

• Spark (no cost). You can use the free products and the free quotas of paid products such as Firestore and Hosting. You cannot deploy Cloud Functions or use paid Google Cloud products. If a product exceeds its free quota, Firebase shuts that product off for the rest of the month rather than charging you. That protects your wallet but can take your app down.

• Blaze (pay as you go). The same free quotas, then you pay for what you use. It unlocks Cloud Functions, Cloud Run, Pub/Sub and other paid Google Cloud products. Linking a Cloud Billing account upgrades the project automatically.

In practice almost every production app ends up on Blaze, because server-side logic (sending receipts, calling a payment API, moderating content) needs Cloud Functions. Moving to Blaze does not by itself cost anything. It removes the safety stop, which is why the budget advice later in this guide matters.

What is free, and what is not

Free on both plans: Cloud Messaging (push notifications), the free Firestore quotas above, 50,000 MAU of email, social and anonymous sign-in, and 1 GB of Realtime Database storage. Realtime Database is capped at 100 simultaneous connections on Spark and 200,000 per database on Blaze, and charges $5 per GB stored beyond the free gigabyte.

Paid, and easy to underestimate:

• Phone authentication. Billed per SMS sent, with the first ten a day free. The price depends on the destination country: $0.04 per SMS to the UK, $0.01 to the US, $0.07 to India. Some countries cost many times more, and Google publishes the full list.

• Cloud Functions. 2 million invocations a month are free, then $0.40 per million, plus compute time. Outbound traffic is free up to 5 GB a month, then $0.12 per GB.

• Cloud Storage for files. Newer buckets include 100 GB a month of downloads free, but the no-cost quotas apply only to buckets in us-central1, us-west1 and us-east1. A bucket in London does not get them.

• Egress. Data leaving Firestore for your users' phones is charged at $0.12 per GiB after the first 10 GiB a month.

Worked monthly estimates for three app sizes

These are our assumptions, not Google's. They describe a typical consumer or marketplace app on Firestore: each active user opens the app 12 times a month; each session reads 60 documents and writes 5; an average document is 2 KB; each user stores about 0.2 MB of data. We assume email or social sign-in, one Cloud Function call per five sessions, and Firestore at us-central1 prices. File storage, third-party services and developer time are excluded.

Arithmetic: reads and writes are billed on the amount above the daily free quota, over 30 days. At 100,000 MAU, (2.4M − 50,000) × 30 = 70.5M reads, which at $0.03 per 100,000 is $21.15. Authentication is 50,000 MAU above the free tier at $0.0055. Function compute time is not itemised on the Firebase pricing page and is not included; at these invocation counts it sits inside the free allowances.

Three things stand out. First, Firestore itself is rarely the problem: at 100,000 MAU the database lines come to about $44 a month in this model. Second, the largest line at 100,000 MAU is the sign-in price once you pass 50,000 MAU. Third, none of this includes building and maintaining the app, which is almost always the real running cost. Magora support starts from £1,000 a month and scales with the scope of the project.

Bill shock 1: read amplification

Firestore bills per document read, not per screen. A query that returns 500 documents costs 500 reads, whether the screen shows 5 of them or all of them. Real-time listeners are charged a read each time a document in the result set is added or updated, and every query costs at least one read even when it returns nothing (Google Cloud).

Take the 10,000 MAU app above, with 120,000 sessions a month. If one screen loads a whole 5,000-document collection with no limit, instead of 60 documents, that is 600 million reads a month. At $0.03 per 100,000 that is about $180 instead of $1.71, from one missing limit(). At 100,000 MAU the same mistake is about ten times larger. Firebase's own guidance lists queries without limits on large result sets among the common causes of excess usage (Firebase, avoiding surprise bills).

The fixes are routine engineering: paginate every list, cache what does not change, keep counters in one document rather than counting a collection, and test against the Firebase Local Emulator Suite before shipping.

Bill shock 2: phone authentication SMS

Email and social sign-in are free up to 50,000 MAU. Phone sign-in is billed per text message sent. In the UK, Google's current rate is $0.04 per SMS, with the first ten each day not billed.

Arithmetic: about 300 SMS a month are free (10 a day); the rest are billed at $0.04. Rates by country are on Google Cloud, Identity Platform pricing; check the country you will actually send to.

At 100,000 MAU, the SMS line in this example is more than twelve times the entire rest of the bill. The practical answer is to offer email or social sign-in first, keep phone verification for cases that truly need it, and ask your developers to rate-limit verification requests.

Bill shock 3: egress and storage

Data sent from Firebase to your users' devices is metered. Firestore gives 10 GiB a month free and then charges $0.12 per GiB. Hosting gives 360 MB a day and then charges $0.15 per GB. A launch that goes viral, or an app that downloads full-size images where a thumbnail would do, shows up here first.

Two choices keep it small. Serve resized images, and decide the storage region deliberately: the free file-storage quota covers only three US regions, so a UK bucket is billed from the start. Region also affects latency and data-residency obligations under UK GDPR, so settle it with your architect rather than on price alone.

Budget alerts: what they do and do not do

Set a budget on day one, but be clear about what you have bought. A standard Google Cloud budget alert sends emails as spend approaches your threshold, and Google states that requests to Firestore succeed even when you have exceeded your monthly budget (Google Cloud). Alerts do not pause services.

Spend caps are different: when spending reaches 100% of the budget, Cloud Billing pauses the service for the rest of the month. At the time of checking they apply only to Firebase AI Logic, App Hosting, Cloud Functions for Firebase and Firebase Extensions, not to Firestore or Authentication (Firebase). For Firestore the protection is monitoring, sensible queries and, if you want a hard stop, automation that uses budget notifications to disable billing.

A sensible starting set: alerts at 50%, 90% and 100% of a monthly budget, sent to two people; a weekly look at the usage dashboard; and one named engineer who owns the bill.

When Firebase stops being the cheap option

Firebase is a strong fit for an MVP: authentication, a database, push and hosting without running servers. The cost model punishes chatty apps and heavy reporting, because every document read is billed. If your product needs complex joins, large analytics queries or strict control of where data lives, a conventional backend on a relational database can cost less per user and be easier to move later. That is a design decision for Discovery, not for after launch.

Platform fees are also only part of the cost of running an app. Maintenance, bug fixes, operating-system updates and monitoring are separate, and for a small app they usually cost more than the Firebase bill. At Magora, support starts from £1,000 a month and scales with the scope of the project.

Firebase pricing: frequently asked questions

Is Firebase free?

Partly. The Spark plan has no charge and includes free quotas, such as 50,000 Firestore reads and 20,000 writes a day, 1 GiB of Firestore storage and 50,000 MAU of sign-in. Cloud Messaging is free. Cloud Functions need the pay-as-you-go Blaze plan, and usage beyond the quotas is billed.

What is the difference between Spark and Blaze?

Spark is the no-cost plan: it cannot deploy Cloud Functions or use paid Google Cloud products, and a product is shut off if it exceeds its free quota. Blaze is pay as you go: the same free quotas, then billing for extra usage, plus access to Cloud Functions and other paid services.

How much does Firebase cost per month for a small app?

In our model, about $0 at 1,000 monthly active users, because usage sits inside the free quotas. At 10,000 users about $2, and at 100,000 about $320, mostly from sign-in charges. Phone sign-in by SMS, unbounded queries and heavy downloads can add far more.

How much does Firebase phone authentication cost?

Phone sign-in is billed per SMS sent, with the first ten a day free. At the time of checking, Google's rate is $0.04 per SMS to the UK, $0.01 to the US and $0.07 to India. Rates vary widely by country.

Does Firebase stop my app when the free limit is reached?

On Spark, yes: that product is shut off for the rest of the month unless you upgrade. On Blaze it keeps running and bills you, even past a budget, because standard budget alerts only send notifications.

How do I avoid a surprise Firebase bill?

Paginate queries, test on the Local Emulator Suite, prefer email or social sign-in to SMS, set budget alerts and use spend caps where they are supported. Review the usage dashboard weekly so you know what normal looks like.

Is Firebase cheaper than building a custom backend?

For an MVP, usually yes, because you avoid server set-up and maintenance. At scale it depends on the access pattern: a read-heavy app can become expensive on Firestore, while a conventional backend has more predictable costs. We compare both options during Discovery.

Can Magora build and run our Firebase app?

Yes. Magora builds mobile apps and MVPs on Firebase or custom backends and offers ongoing support. Support starts from £1,000 a month and scales with the scope of the project.