<p><span class="h-card" translate="no"><a href="https://fosstodon.org/@kev" class="u-url mention">@<span>kev</span></a></span> if you can self host Uptime Kuma that might work (<a href="https://github.com/louislam/uptime-kuma" target="_blank" rel="nofollow noopener noreferrer" translate="no"><span class="invisible">https://</span><span class="ellipsis">github.com/louislam/uptime-kum</span><span class="invisible">a</span></a>). Pingdom is just over £7.</p>