Implementing Authentication with Firebase in a Vue.js App

Introduction: Cold Coffee, Warm Firebase

There I was. Staring at the screen. Coffee cold. Brain fried. Just trying to figure out how to log a user in.

“Why,” I whispered to the JavaScript gods, “does this have to be so complicated?”

Enter: Firebase Authentication—the hero I didn’t know I needed.

Why Firebase + Vue?

• Vue.js: Like your favorite hoodie—comfortable, flexible, and doesn't judge you for nesting components wrong.
• Firebase Auth: A plug-and-play backend with:
  • Email/password auth
  • OAuth (Google, GitHub, etc.)
  • Anonymous users (commitment-phobes, rejoice)
  • Magic links and password resets

Step-by-Step: From 0 to Login Flow in Under an Hour

Step 1: Firebase Setup

Go to the Firebase Console, create a new project, and enable the authentication methods you need.

Step 2: Install Firebase in Vue

npm install firebase

Step 3: Initialize Firebase

// src/firebase.js
import { initializeApp } from 'firebase/app'
import { getAuth } from 'firebase/auth'

const firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "your-project.firebaseapp.com",
  projectId: "your-project-id",
  appId: "your-app-id"
}

const app = initializeApp(firebaseConfig)
export const auth = getAuth(app)

Signup Component (Composition API + Firebase)

<script setup>
import { ref } from 'vue'
import { createUserWithEmailAndPassword } from 'firebase/auth'
import { auth } from '../firebase'

const email = ref('')
const password = ref('')
const error = ref(null)

const signup = async () => {
  try {
    await createUserWithEmailAndPassword(auth, email.value, password.value)
  } catch (err) {
    error.value = err.message
  }
}
</script>

<template>
  <form @submit.prevent="signup">
    <input v-model="email" placeholder="Email" />
    <input v-model="password" placeholder="Password" type="password" />
    <button>Sign Up</button>
    <p v-if="error">{{ error }}</p>
  </form>
</template>

No password hashing. No backend. No tears.

Realtime Auth State Monitoring

import { onAuthStateChanged } from "firebase/auth"

onAuthStateChanged(auth, (user) => {
  if (user) {
    console.log("User logged in:", user)
  } else {
    console.log("User logged out")
  }
})

Real Case Study: My Mom, The QA Tester

I handed my journaling app to my mom. She:

• Created an account
• Logged in
• Clicked “Forgot Password”
• Got an email reset link

"Wow. This feels like a real app." — Mom

(Me, tearing up silently in a corner.)

Pros of Firebase Auth in Vue

Security baked in (OAuth, 2FA, etc.)

No backend required

Perfect for MVPs or solo projects

Managed by Google = peace of mind

The Not-So-Sweet Bits

It’s Google

Not everyone is okay handing user data to the Big G.

Vendor lock-in

Migrating off Firebase later isn’t impossible—but it’s not fun.

Limited deep customization

Want crazy RBAC or custom claims? Be ready to write Firebase Functions.

Where Firebase + Vue Can Go

• SaaS apps with protected routes
• Firestore + Auth for per-user data
• Email verification, analytics, A/B tests
• Vue Router auth guards for private pages

Conclusion: Should You Use Firebase Auth?

Yes.

Especially if:

• You want to skip backend auth boilerplate
• You need something secure that just works
• You’re building alone or iterating fast

Firebase Auth helped me:

• Skip weeks of backend dev
• Build something secure
• Impress my mom

You deserve that kind of win. So go ahead—use Firebase. Sleep better. Code happier.

<!-- One last tip -->
<template>
  <p>If it works for your mom, it'll work for your users too.</p>
</template>