Alternatives to UptimeRobot

Small free bot that checks the sites you add every 5 minutes and alerts you the moment one goes down or comes back. No account needed beyond starting a chat with the bot.

The Telegram delivery bot for StatusCake, a UK uptime and performance monitor with an official Telegram integration: alerts land in chat the moment a StatusCake test fails or recovers. Monitors are still created on statuscake.com; the free plan covers a handful of tests.

Runs on-demand ping and HTTP checks for any host from a dozen locations worldwide, right inside the chat — no account needed. Free, English interface, useful for a quick 'is it just me' check on a site or server.

Sends a domain name and get an instant WHOIS lookup: registrar, hosting provider and ASN, without opening a web-based whois tool. Free, no ads, no sign-up.

Open-source bot that checks whether a website is up right now, or keeps tracking a URL and pings you the moment it goes down. Free, no sign-up, source code published on GitHub.

Independently run bot that watches sites you register and pings you if anything looks wrong. Free, minimal setup, run by a single developer rather than a company.

Bare-bones bot that checks whether a server or site you point it at is online, and lets you know if it drops. Free, minimal features, best for a single personal server rather than a fleet.