Google Firebase · Rate Limits

Google Firebase Rate Limits

Firebase services run on Google Cloud and inherit per-service quotas. The most actionable per-service limits are summarized below. Spark plan caps absolute usage at the free quota; Blaze plan removes the hard caps but retains per-service operational ceilings (e.g., Firestore writes-per-second per document, Realtime Database concurrent connections, Cloud Functions max instances). Quotas are raisable via the Cloud Console quotas page.

Google Firebase Rate Limits is the machine-readable rate-limit profile for Google Firebase on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 11 rate-limit definitions, measuring writes_per_second, concurrent_connections, concurrent_invocations, GB_per_month, and GB_per_day.

The profile also includes 5 backoff/retry policies defined and response codes documented for throttled, quotaExceeded, and resourceExhausted.

Tagged areas include Mobile Backend, Serverless, Realtime Database, Google Cloud, and Rate Limiting.

11 Limits Throttle: 429 Quota: 403
Mobile BackendServerlessRealtime DatabaseGoogle CloudRate Limiting

Limits

Firestore writes per second per document document
writes_per_second · second
1
Soft limit; sustained higher write rate to a single document causes contention.
Firestore writes per second per index field index-field
writes_per_second · second
500
Realtime Database concurrent connections (Spark) database
concurrent_connections
100
Realtime Database concurrent connections (Blaze) database
concurrent_connections
200000
Realtime Database simultaneous writes database
writes_per_second · second
1000
Approximate sustained ceiling; throughput depends on write size.
Cloud Functions max concurrent invocations (default) function
concurrent_invocations
1000
Default per-function concurrency; raisable via Cloud Console.
Cloud Functions outbound networking (free) project
GB_per_month · month
5
Cloud Storage download (free Spark) project
GB_per_day · day
1
Hosting daily data transfer (free Spark) site
MB_per_day · day
360
Authentication monthly active users (free) project
MAU · month
50000
Beyond 50K MAU, Identity Platform pricing applies (Auth with IdP upgrade).
Cloud Messaging (FCM) topic-message rate app
requests_per_second · minute
600000
Per-project topic message ceiling; check current FCM docs for exact value.

Policies

Spark plan hard caps
On the Spark plan, when a free quota is exhausted, the service stops responding (or returns quota errors) until the next reset. There is no overage; upgrade to Blaze to continue.
Blaze plan soft caps
On Blaze, free quotas are deducted first; usage above is billed at GCP rates. Per-service operational limits (concurrency, document write rate) remain and may need quota raises for production.
Quota raises
Most operational quotas (Cloud Functions concurrency, Firestore index counts, Realtime Database connections via sharding) can be raised through the Cloud Console quotas page on Blaze.
Backoff strategy
Implement exponential backoff with jitter on 429 / 403; for Firestore, use sharded counters and randomized document IDs to spread write load.
Auth pricing transition
Authentication transitions to Identity Platform pricing above 50K MAU; review Identity Platform per-MAU rates if scaling beyond the free tier.

Sources