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Check the website is a service that notify you when websites down. It's totally free. 

You can get notify by email, slack, telegram, desktop application and browser extension.

You can create daily, weekly and monthly report with 7 different locations around the world.
Custom Status Page,
Customizable status badges,
Support Native Desktop Application (Windows,Mac, Linux)
Support Chrome Extension,
Free for personal and commercial usage
Up to 25 websites allowed,
Slack Notification,
Email Notification,
Browser Notification,
Generate Bulk Lighthouse,
Developer Friendly API
Webhook Support