1. Cheap uptime and performance monitoring with detailed reporting and flexible alerting

  2. Free Website Uptime Monitoring

  3. updown.io is a HTTP(S)/TCP/ICMP monitoring service which checks periodically the URL you want and reports back any anomaly.

  4. StatusCake | Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring

  5. RapidSpike is an uptime and performance monitoring service for websites and web applications.

  6. Affordable uptime monitoring service for webmasters and website owners. Have your website or server checked every minute and get alerted instantly.

    paid Free Trial $5.99 / Monthly (1 check)

  7. Uptime & performance monitoring for websites and APIs.

  8. Uptrends is a website and mobile app that allows you to monitor your website. You can use it to both monitor the security and performance of your website as well as the activity on your site. Read more about Uptrends.

  9. With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.

  10. Free service to send SSL certificate expiration alerts

  11. Site24x7 offers both free & paid website monitoring services. Monitor websites remotely and receive instant email/sms alerts if your website becomes unavailable. View uptime & performance graphs of your website monitors.

  12. A pain-free service to add SSL to your site, for non-geeks