Free Website Uptime Monitoring with Google Sheets

 is an open-source project written in Google Apps Script that lets you monitor the uptime and downtime of your website from a Google Sheet.

Internally, the Google Script sets up a time-based trigger that runs every few minutes and connects to the specified website using the UrlFetchApp service of Google Apps Script. If the response code is not 200, it alerts the owner via Gmail.

The source code of Website Monitor is available on Github. You can extend the script with the Twilio API and get SMS alerts similar to commercial website monitoring services like Pingdom or Zoho's Site 24x7.