No-cost Firebase plan with a Cloud Firestore database (1 GiB, 50,000 reads and 20,000 writes a day), Authentication and Hosting (10 GB storage, 10 GB transfer a month); Cloud Storage now needs Blaze. Realtime Database adds 100 simultaneous connections, 1 GB stored and 10 GB downloaded a month.
Free allowance
What the free plan includes, as the provider states it.
- Firestore stored data · Document database
- 1 GB
- Firebase gives this quota as 1 GiB of stored data (shown here as 1 GB). Cloud Firestore allows exactly one free database per project.
- Firestore document reads / day · Document database
- 50K
- Daily quotas reset around midnight Pacific time.
- Firestore document writes / day · Document database
- 20K
- Document deletes have a separate 20,000 per day quota.
- monthly active users · Authentication
- 50K
- Firebase lists this for Authentication with Identity Platform: no cost up to 50K monthly active users.
- daily active users (Identity Platform) · Authentication
- 3K
- Counts Tier 1 daily active users only. It is a daily limit for Firebase Authentication with Identity Platform on the Spark plan.
- Hosting storage · Static site
- 10 GB
- New deploys fail at the limit.
- Hosting data transfer / month · Static site
- 10 GB
- Sites are disabled after a short grace period at the limit.
- Realtime Database simultaneous connections at once · Realtime messaging
- 100
- Counts open realtime connections (WebSocket, long polling and server-sent events), not REST requests. The limit cannot be raised on Spark; at the limit, new connections are rejected until existing ones close, while connected users keep working.
- Realtime Database stored data · Realtime messaging
- 1 GB
- Excludes Hosting and data stored by other Firebase products. When a Spark project goes over a plan limit, Firebase turns the app off to prevent further usage.
- Realtime Database downloads / month · Realtime messaging
- 10 GB
- Counts all bytes downloaded from the database, including protocol and encryption overhead. Going over turns the app off until the limit resets at the start of the next billing cycle, unless the project upgrades to Blaze.
The fine print
Each verdict links to the quote it rests on.
- Free for
- As long as you stay within the limits
- At the limit
- Anything over the limit is refused until the next period
- Spending cap
- None needed: the free plan cannot bill you
- Idle projects
- No pause rule documented
- Data retention
- No deletion rule documented
- Card at sign-up
- Not required
- Identity check
- An email address
- Commercial use
- Not stated
- Mainland China
- Partly reachableGreatFire: firestore.googleapis.com and the Firebase Auth endpoint identitytoolkit.googleapis.com are intermittent; *.firebaseio.com (Realtime Database) is mixed, with many tested URLs blocked; the Hosting defaults *.web.app and *.firebaseapp.com are mixed, mostly intermittent or accessible. Custom domains were not assessed.
- Sign-up regions
- No restrictions documented
- Quotas apply per
- Project
Alternatives
Other free plans for the same need, ranked by the same neutral rules.
Changes
- Correction
Better: Mainland China reachability corrected: not verified → partly reachable
- Correction
Worse: Free connections corrected: not listed → 100 / concurrent
- Correction
Worse: Free storage corrected: not listed → 1 GB
- Correction
Worse: Free bandwidth corrected: not listed → 10 GB / month
- Correction
Better: Behaviour at the limit corrected: project paused → requests refused
- Oct 15, 2026
- Awaiting review
- Spark