How to Run Python Flask App Online using Ngrok?

Ngrok is a tool that creates a secure tunnel between your local machine and the internet. It allows developers to expose their local web server to the internet without deploying it to a remote server. Python Flask lets you create web applications locally, but with Ngrok, you can showcase them online instantly.

Step 1: Install Ngrok

Download Ngrok from its official website (https://ngrok.com/download) for your operating system (Windows/macOS/Linux). Extract the archive to your preferred folder location.

Step 2: Create a Flask App

Create a new Python file called app.py with a simple Flask application ?

from flask import Flask

app = Flask(__name__)

@app.route('/')
def hello():
    return 'Hello, World!'

if __name__ == '__main__':
    app.run(port=5000)

Step 3: Run the Flask App Locally

Start your Flask application by running this command in your terminal ?

python app.py

Test the app by visiting http://localhost:5000 in your browser. You should see "Hello, World!" displayed.

 * Running on http://127.0.0.1:5000
 * Debug mode: off

Step 4: Start Ngrok

Open a new terminal window and navigate to the Ngrok folder. Run the following command to create a tunnel to your Flask app ?

./ngrok http 5000

On Windows, use:

ngrok.exe http 5000

Ngrok will display a public URL (like https://abc123.ngrok.io) that tunnels to your local Flask app.

Step 5: Access Your Flask App Online

Copy the HTTPS URL provided by Ngrok and share it with anyone. They can access your Flask app from anywhere in the world using this URL.

Common Use Cases

Security Considerations

Remember that Ngrok exposes your local application to the internet. For production use:

• Use authentication on your Flask routes

• Consider Ngrok's paid plans for password protection

• Never expose sensitive data through public Ngrok URLs

• Stop Ngrok tunnels when not in use

Conclusion

Ngrok provides an excellent solution for running Flask apps online without deployment. It's perfect for testing, demonstrations, and sharing your work instantly with anyone worldwide.