Current documented limits
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| generation-specific function durationGeneration and trigger type determine the ceiling. | 1st gen: 540s; 2nd gen HTTP: 60m; scheduled: 30m; event: 540s | Cloud Functions for Firebase | FirebaseAug 22, 2026 |
| Hosting request timeoutThe Hosting request can time out before a longer Cloud Run backend maximum. | 60 seconds | Hosting rewrites to serverless | FirebaseAug 22, 2026 |
| document sizeIndex entries and field-value indexing have separate size constraints. | 1 MiB | Cloud Firestore | FirebaseAug 22, 2026 |
| maximum API requestTransactions and commits also have time and transformation constraints. | 10 MiB | Cloud Firestore | FirebaseAug 22, 2026 |
| transaction durationIdle time can end a transaction well before the total-duration ceiling. | 270 seconds; 60-second idle expiration | Cloud Firestore | FirebaseAug 22, 2026 |
| index configuration and entriesSingle-field configurations and entry byte sizes impose additional ceilings. | 200 composite indexes without billing; 1,000 with billing; 40,000 entries/document | Cloud Firestore | FirebaseAug 22, 2026 |
How to apply Firebase limits safely
The monitored baseline covers generation-specific function duration, Hosting request timeout, document size, maximum API request, transaction duration, index configuration and entries. Treat these as separate constraints rather than one platform-wide capacity number: a workload can fit one row and still fail another because the plan, model, endpoint, runtime, region, invocation mode, or account scope differs.
- Match the production workload to the exact scope printed beside each value and confirm it in the active Firebase console, configuration, or response headers.
- Measure the serialized request, token volume, duration, concurrency, storage, or connection demand at realistic percentiles, then preserve headroom for bursts and retries.
- Check every adjacent layer—client, SDK, gateway, proxy, queue, database, and downstream service—for a smaller effective limit before changing architecture.
Specific limit pages
These pages exist because the constraint has a distinct implementation or troubleshooting intent. Closely related keyword variations stay consolidated.
Firebase Function Timeout Limits
Firebase Function Timeout Limits, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.
Firebase Hosting Serverless Timeout
Firebase Hosting Serverless Timeout, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.
Cloud Firestore Document Size Limit
Cloud Firestore Document Size Limit, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.
Cloud Firestore API Request Size
Cloud Firestore API Request Size, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.
Cloud Firestore Transaction Time Limit
Cloud Firestore Transaction Time Limit, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.
Cloud Firestore Index Limits
Cloud Firestore Index Limits, verified against Firebase's official documentation with scope, implementation impact, caveats, and a direct check.