Deploying Flutter Web to Firebase Hosting with GitHub Actions CI/CD
Why Firebase Hosting?
| Option | Pros | Cons |
|---|---|---|
| Firebase Hosting | Free, auto-HTTPS, CDN, easy GitHub Actions | Google dependency |
| Vercel | Feature-rich | Flutter-specific config is complex |
| GitHub Pages | Free | Manual HTTPS setup |
For Flutter Web, Firebase Hosting is the fastest path to production.
1. Firebase CLI Setup
npm install -g firebase-tools
firebase login
cd your-flutter-project
firebase init hosting
Answer firebase init hosting:
- Public directory:
build/web - Configure as SPA: Yes
- Automatic builds via GitHub: No (we'll configure manually)
2. firebase.json Configuration
{
"hosting": {
"public": "build/web",
"ignore": ["firebase.json", "**/.*", "**/node_modules/**"],
"rewrites": [
{ "source": "**", "destination": "/index.html" }
],
"headers": [
{
"source": "**/*.@(js|css|wasm)",
"headers": [
{ "key": "Cache-Control", "value": "max-age=31536000" }
]
}
]
}
}
rewrites → all routes serve index.html (required for Flutter's client-side router).
headers → JS/WASM cached for 1 year (safe because filenames are hashed per build).
3. GitHub Actions Workflow
# .github/workflows/deploy-prod.yml
name: Deploy to Production
on:
push:
branches: [main]
paths: ['lib/**', 'web/**', 'pubspec.yaml']
paths-ignore: ['docs/**', '**.md']
concurrency:
group: deploy-prod
cancel-in-progress: false # queue all commits
jobs:
deploy:
runs-on: ubuntu-latest
timeout-minutes: 30
steps:
- uses: actions/checkout@v4
- uses: subosito/flutter-action@v2
with:
flutter-version: '3.32.x'
channel: stable
cache: true
- run: flutter build web --release --web-renderer canvaskit
- uses: FirebaseExtended/action-hosting-deploy@v0
with:
repoToken: ${{ secrets.GITHUB_TOKEN }}
firebaseServiceAccount: ${{ secrets.FIREBASE_SERVICE_ACCOUNT }}
channelId: live
projectId: your-project-id
4. Service Account Secret
# Firebase Console → Project Settings → Service Accounts
# → Generate new private key → Download JSON
# GitHub repo → Settings → Secrets → FIREBASE_SERVICE_ACCOUNT → paste JSON
5. Verify the Deployment
# Check deploy status
gh run list --workflow=deploy-prod.yml --limit 3
# Confirm live URL
curl -I https://your-project.web.app/
Concurrency Note
With multiple parallel instances pushing to main, set cancel-in-progress: false. All commits queue and deploy in order — no commit gets skipped.
Cost
Firebase Hosting free tier:
- 10 GB/month transfer
- 1 GB storage
Solo SaaS traffic is well within free tier.
Summary
-
firebase init hosting→ point tobuild/web - SPA rewrites + long-cache headers in
firebase.json - GitHub Actions:
flutter build web --release→firebase deploy - Store service account JSON as
FIREBASE_SERVICE_ACCOUNTsecret
First deploy to live URL in under 30 minutes.
Building in public: https://my-web-app-b67f4.web.app/
