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Backend & Infrastructure

Firebase Setup Guide: Add Firebase to Android and Web

Firebase connects your app to Google's backend services — authentication, databases, storage, and more. This guide walks through creating a Firebase project and integrating it into an Android or web application from scratch.

Step 1: Create a Firebase Project

  1. 1Go to console.firebase.google.com and sign in with your Google account.
  2. 2Click Add project, enter a project name, and optionally enable Google Analytics.
  3. 3Wait for project creation to complete, then click Continue.

Step 2: Register Your App

From the Project Overview page, click the platform icon to register your app:

Android

  1. Click the Android icon
  2. Enter your app's package name (e.g. com.example.myapp)
  3. Optionally add a nickname and SHA-1 fingerprint
  4. Download google-services.json
  5. Place it in your app/ directory

Web

  1. Click the web icon </>
  2. Enter an app nickname
  3. Optionally set up Firebase Hosting
  4. Copy the Firebase config object shown

Step 3: Add Firebase SDK

Android (Gradle)

// Project-level build.gradle (or settings.gradle with plugins block)
plugins {
    id("com.google.gms.google-services") version "4.4.0" apply false
}

// App-level build.gradle
plugins {
    id("com.google.gms.google-services")
}

dependencies {
    // Firebase BoM — manages version compatibility
    implementation(platform("com.google.firebase:firebase-bom:33.1.0"))
    implementation("com.google.firebase:firebase-analytics")
    // Add other Firebase products as needed:
    // implementation("com.google.firebase:firebase-auth")
    // implementation("com.google.firebase:firebase-firestore")
}

Web (npm)

npm install firebase

// src/firebase.js
import { initializeApp } from 'firebase/app';
import { getFirestore } from 'firebase/firestore';

const firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "YOUR_PROJECT.firebaseapp.com",
  projectId: "YOUR_PROJECT_ID",
  storageBucket: "YOUR_PROJECT.appspot.com",
  messagingSenderId: "YOUR_SENDER_ID",
  appId: "YOUR_APP_ID"
};

const app = initializeApp(firebaseConfig);
export const db = getFirestore(app);

Step 4: Verify the Setup

Run your app. If Firebase is configured correctly, you should see your app appear in the Firebase Console under the project overview within a few minutes of the first launch.

Common setup errors

  • Wrong google-services.json location — must be in app/
  • Package name mismatch between the JSON and your app's applicationId
  • Missing Google Services plugin in build.gradle
  • Stale config file — re-download from Firebase Console after adding services

Next Steps

  • Enable Authentication in the Firebase Console and add sign-in providers
  • Set up Firestore or Realtime Database and write Security Rules
  • Configure Cloud Storage for file uploads
  • Add Firebase App Check to prevent unauthorized API access

Related Resources

Google Services JSON ToolAndroid Firebase ConfigFirebase Security
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Written by Zhisan

Independent Developer · Last updated June 2026