Connect monitoring of your site for free the first 30 days. You can get great functionality for monitoring your sites in free testing mode.
You can also manually check the performance of any site. Look at the statistics on the speed of loading pages of this forum.
Full functionality in automatic mode is available by paid subscription.
The host-tracker is 30 days of free monitoring of the site and server:
100 URL Check every 1 minute;
Monitor Response Time;
10 contacts, Unlimited alerts, 25 free SMS/month;
DNS Blacklist Check;
Domain and Certificate, Expiration Monitoring;
CPU, RAM, HDD Load Monitor;
Full log, Error snapshotting.