Alternatives to AlertSite

HetrixTools suits individuals and teams that need uptime, server, blacklist, domain, SSL, or nameserver monitoring.

Better Stack

It suits teams coordinating incident response, on-call coverage, uptime checks, and telemetry.

WebSitePulse suits teams that need to monitor infrastructure, websites, transactions, or email across multiple locations.

Catchpoint Internet Performance Monitoring

The platform is intended for digital enterprises monitoring customer experience, workforce efficiency, networks, websites, applications, or APIs.

Checkly

Checkly is intended for developers, SRE and platform teams, QA engineers, and engineering managers monitoring APIs or user interfaces.

Exoprise suits organizations monitoring employee experience across cloud apps, endpoints, and networks.

It suits people who need self-hosted uptime, DNS or synthetic monitoring with status pages and many notification options.

UptimeRobot

The free tier suits hobby and nonprofit projects that need up to 50 monitors and can use five-minute checks.

Uptrends

Core is described for teams needing regional availability and performance monitoring, while Pro is aimed at SRE and Ops teams.

Site24x7 suits IT and DevOps teams monitoring public websites or internal sites behind firewalls.