Is Firebase really free?

If you look at the Firebase pricing plan you can see that data is the main constraint for the pricing brackets . When you move up a tier you get various increases in data allowances as well as more database operations. This means you need to look at what your app does to see the impact of more users.

For 50,000 app installs (5,000 Daily Active Users): $12. 14/month Read/Write CostsTotal monthly cost = $11.10/month$0.21 / day * 30 = $6.30100K total daily writes.8 * $0.18$0.14 / day * 30 = $4.20100K total daily deletes.8 * $0.02See a Cloud Firestore pricing example | Firebase Documentation firebase.google.com › docs › firestore › billing-example

Firebase offers a no-cost tier pricing plan for all its products . For some products, usage continues at no cost no matter your level of use. For other products, if you need high levels of use, you’ll need to switch your project to a paid-tier pricing plan.