How to set spend caps on the Firebase Blaze plan
Last checked 2026-10-20 (ET). Tick each step as you go. Your progress is saved in this browser only.
Firebase projects on the Blaze plan can set spend cap budgets for a few services. They are in Preview, and Firebase is direct about the limits: "Spend caps are not "hard caps"."
Official doc: Set up spend caps for Firebase services
What the Blaze plan changes
- Blaze is Firebase's "pay-as-you-go" plan. A Blaze project "has a Cloud Billing account linked to it."
- On the no-cost Spark plan, "If you exceed the no-cost quota limit in a calendar month for any product, your project's usage of that specific product will be shut off for the remainder of that month." On Blaze, extra usage is billed instead.
- Some actions move a project to Blaze without the upgrade button. Firebase lists "Linking a Cloud Billing account to your project from within the Google Cloud console" and "Using Google Cloud services (like Pub/Sub or Cloud Run) or Google Maps APIs in the same project."
- Firebase says "budget alerts do not cap your usage or charges." For AI Logic, App Hosting, Cloud Functions and Extensions, Firebase says "we strongly recommend that you also set up spend caps."
Official doc: Firebase pricing plans
Services you can cap
- Firebase AI Logic (caps on the Gemini Developer API or the Agent Platform Gemini API, formerly Vertex AI)
- Firebase App Hosting
- Cloud Functions for Firebase (caps the underlying Cloud Run functions service)
- Firebase Extensions (caps the underlying Cloud Run functions service)
A cap on an underlying service applies to the whole project. For example, a cap on the Agent Platform Gemini API also covers usage through Genkit or ADK in that project, not just AI Logic.
Who can set it
You need admin-level access to the project and its Cloud Billing account, for example the Billing Account Administrator role on the linked billing account.
Set a spend cap
Each cap covers one project and one service, and runs monthly from the first day of the month. You can also set caps in the Google Cloud console. How Google Cloud spend caps work.
What the cap does
- At 50% and 80%, Cloud Billing emails all billing administrators, project owners and any applicable "essential contact."
- At 100%, it pauses new usage of that service for the rest of the month and sends another email. The consoles show a banner.
- Your app will get errors from the paused service, so handle them in code.
- The cap resets at the start of the next month. You can also lift it early.
What it does not do
- It is not instant. Firebase says enforcement "can be delayed by several minutes. Any cost overages incurred during this delay will be billed."
- It is Preview, so it "isn't subject to any SLA or deprecation policy."
- Other Firebase and Google Cloud services are not covered. For those you only get alerts-only budgets, which "do not pause services."
- Editing a cap, even renaming it in the Google Cloud console, sets it back to Configured. If you have already passed the amount, it enforces right away.
Where CapBrake helps
Firebase does not give you one hard cap on your whole bill, so alerts still matter. Use the free CapBrake checklist to tick off each step above. Your progress is saved in your browser. No account and no credentials.
CapBrake also has an alert relay for providers like Firebase. It is free in early access. You put a private relay address on your budget alerts, and CapBrake sends each alert to your browser or Slack. CapBrake will never ask for your Firebase credentials.