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   * [newrelic.com](https://www.newrelic.com) — New Relic observability platform built to help engineers create more perfect software. From monoliths to serverless, you can instrument everything, then analyze, troubleshoot, and optimize your entire software stack. Free tier offers 100GB/month of free data ingest, 1 free full access user, and unlimited free basic users.
   * [nixstats.com](https://nixstats.com) - Free for one server. E-Mail Notifications, public status page, 60 second interval and more.
   * [nodequery.com](https://nodequery.com/) — Free basic server monitors up to 10 servers
+  * [OnlineOrNot.com](https://onlineornot.com/) - 10 uptime monitors with a 5 minute interval, 1 page speed monitors with a 12 hour interval. Free alerts via Slack and Email.
   * [opsgenie.com](https://www.opsgenie.com/) — Powerful alerting and on-call management for operating always-on services. Free up to 5 users.
   * [paessler.com](https://www.paessler.com/) — Powerful infrastructure and network monitoring solution including alerting, strong visualization capabilities and basic reporting. Free up to 100 sensors.
   * [pagertree.com](https://pagertree.com/) - Simple interface for alerting and on-call management. Free up to 5 users.