30 Sept 2023

Building a URL Monitoring Tool with Python

In today's digital age, websites play a crucial role in the success of businesses and organizations. Ensuring the availability and performance of websites is essential to maintain a positive user experience and retain customers. To achieve this, monitoring the uptime and response times of websites becomes crucial. In this blog, we will guide you through building a simple URL monitoring tool using Python, which will help you track the availability of websites and notify you in case of any downtime.

Table of Contents

1. Introduction

2. Setting up the Environment

3. Understanding the URL Monitoring Tool

4. Building the URL Monitoring Tool

5. Testing the Tool

6. Conclusion


Why URL Monitoring is important

Monitoring the availability of websites is essential for various reasons, including

  1. Uptime Management: Tracking website availability helps ensure that the website is up and running, reducing the risk of potential revenue loss due to downtime.
  2. User Experience: Continuous monitoring allows you to identify and address performance issues, providing a better user experience.
  3. Alerts for Downtime: The monitoring tool can notify website administrators when downtime occurs, allowing them to address the issues promptly.
  4. Data for Analysis: Data collected through monitoring can be analyzed to identify patterns and potential improvements in website performance.

Tools and technologies to be used

For this project, we will use Python as our programming language due to its simplicity, versatility, and the availability of libraries that make web monitoring easy. Additionally, we will use the Requests library to make HTTP requests and check website availability. The script will send notifications using the popular Slack messaging platform.

Setting up the Environment

Installing Python

If you don't have Python installed, head over to the official Python website (https://www.python.org/) and download the latest version compatible with your operating system. Follow the installation instructions to set up Python on your machine.

Choosing an IDE (Integrated Development Environment)

For writing and testing Python code, you can use any code editor or IDE you prefer. Some popular choices include Visual Studio Code, PyCharm, or Jupyter Notebook. Pick the one that suits your needs best and ensure that you have it installed.

Understanding the URL Monitoring Tool

How the tool works

Our URL monitoring tool will follow these basic steps

1. We will provide a list of URLs that we want to monitor.
2. The script will send HTTP requests to each URL and check for successful responses (status code 200).
3. If a website is down or returns an error status, the script will notify the website administrators through Slack.

Technologies used

Python: The programming language used to build the monitoring tool.
Requests Library: A Python library to make HTTP requests easily.
Slack API: We will use Slack's API to send notifications to a specific channel.

Building the URL Monitoring Tool

Setting up the project structure

Create a new folder for the project and organize the files as follows

   ├── main.py
 └── requirements.txt

Installing required libraries

Before we start writing the code, install the necessary libraries. Open your terminal or command prompt, navigate to the project folder, and execute the following command

pip install requests

Writing the code

Now, let's start building our URL monitoring tool by writing the Python code in main.py

# Import required libraries
import requests
import time

# Define the list of URLs to monitor
URLs = [
    # Add more URLs to monitor

# Slack webhook URL (you'll need to create a Slack app and obtain this URL)

def check_urls():
    for url in URLs:
            response = requests.get(url)
            if response.status_code == 200:
                print(f'{url} is UP')
                send_slack_notification(f'{url} is DOWN (Status Code: {response.status_code})')
        except requests.ConnectionError:
            send_slack_notification(f'{url} is DOWN (Connection Error)')
def send_slack_notification(message):
    payload = {'text': message}
    requests.post(SLACK_WEBHOOK_URL, json=payload)

if __name__ == '__main__':
    while True:
        # Check URLs every 5 minutes (adjust the interval as needed)

Testing the Tool

Running the monitoring tool

To start the URL monitoring tool, simply run the main.py script using the following command

python main.py

The script will continuously monitor the provided URLs and notify you via Slack if any website is down or returns an error status.

Handling notifications

To set up Slack notifications, you'll need to follow these steps

  1. Create a Slack app: Go to https://api.slack.com/apps and create a new app for your workspace.
  2. Add Incoming Webhooks: In the app settings, navigate to "Incoming Webhooks" and activate it. Create a new webhook and select the channel where notifications will be sent.
  3. Obtain the Webhook URL: Once the webhook is created, you'll receive a Webhook URL. Replace 'YOUR_SLACK_WEBHOOK_URL' in the main.py code with this URL.


In this tutorial, we have built a simple URL monitoring tool using Python that allows us to track the availability of websites and receive notifications in case of downtime. We utilized the Requests library for making HTTP requests and the Slack API for sending notifications to a Slack channel.

This URL monitoring tool can be extended and customized further to suit specific requirements. For instance, you can add more advanced error handling, implement email notifications, or store monitoring data in a database for historical analysis.

Remember to run the script on a server or a machine that remains online constantly to ensure continuous monitoring. Regularly monitoring websites is a proactive approach to maintain the reliability and performance of your online presence, helping you deliver a seamless user experience to your visitors.