UptimeRobot

UptimeRobot offers a comprehensive website monitoring service, designed to alert you the moment your website experiences downtime. Be the first to know if your site is down, allowing you to address issues before they significantly impact your users or revenue. The service includes various monitoring types:

• Website monitoring: Checks your site's availability at regular intervals.
• SSL monitoring: Notifies you 30, 14, and 7 days before your SSL certificate expires, preventing visitor warnings and potential loss of trust.
• Domain expiration monitoring: Helps you keep track of your domain's expiry to avoid service interruption.
• Cron job monitoring (heartbeat monitoring): Ensures your recurring background tasks and connected intranet devices are functioning correctly.
• Port monitoring: Verifies the status of specific services like email or database servers by checking their ports.
• Ping monitoring: Uses standard ping checks to assess the availability of network devices.
• Keyword monitoring: Checks for the presence or absence of specific text in your website's response body, useful for verifying content integrity.

Advanced features include multi-location checks to prevent false positives, customizable maintenance windows, and response time monitoring to identify performance issues. Get notified through various channels such as email, SMS, Slack, Telegram, Discord, Microsoft Teams, Zapier, and webhooks. You can also create white-labeled status pages to keep your customers informed about incidents and planned maintenance. The service offers a generous free plan with 50 monitors and 5-minute checks.