Hosting a Flask App on Azure App Service — Technology

Overview

This guide walks through deploying a Python Flask app to Azure App Service — from creating the resource to pointing your custom domain at it. No Docker, no VMs, just the simplest path to production.

What you'll need

An Azure subscription (free tier works)
Your Flask app with a requirements.txt
Azure CLI installed locally

Step 1 — Create the App Service

In the Azure Portal, search for App Services and click Create. Choose your subscription, create or select a Resource Group, give it a name (this becomes your *.azurewebsites.net URL), and select Python 3.9 on Linux.

For the pricing plan, Basic B1 (~$13/month) is the sweet spot for a personal app — it stays always-on unlike the Free tier.

Step 2 — Prepare your app

Add a requirements.txt at your project root:

flask==3.0.0
gunicorn==21.2.0

Add a startup command. In App Service → Configuration → General Settings, set:

gunicorn --bind=0.0.0.0 --timeout 600 server:app

Step 3 — Deploy via zip

The simplest deploy method — zip your project and push it:

cd your-project-folder
zip -r deploy.zip . -x "*.db" -x "__pycache__/*" -x ".git/*"

az webapp deployment source config-zip \
  --resource-group YOUR_RG \
  --name YOUR_APP_NAME \
  --src deploy.zip

Exclude your .db files from the zip — you'll upload those separately via the Kudu file browser so your data doesn't get overwritten on each deploy.

Step 4 — Add your custom domain

In App Service → Custom Domains, click Add custom domain. Azure will give you a CNAME value to add at your DNS provider (Squarespace, Cloudflare, etc.). Once the DNS propagates, come back and click Validate.

Step 5 — Free SSL certificate

Once the domain is verified, go to TLS/SSL Settings → Private Key Certificates → Create App Service Managed Certificate. Select your domain, hit Create — Azure handles renewal automatically.

Done

Your Flask app is now running at https://yourdomain.com with auto-renewing SSL. Total additional cost: ~$13/month.