UptimeRobot alternative: what changes when you outgrow the free tier

What UptimeRobot does well

Start with the thing that matters most: UptimeRobot has one of the most generous free tiers in the category, at 50 monitors on a five minute interval. That is five times the monitor count on the Undownable free plan, and we are not going to spin it. If you need to watch fifty things for nothing, UptimeRobot wins outright and you should use it.

• Fifty free monitors at five minute intervals, with API access included even on the free plan.
• A very long track record and a large user base, which means the integrations are mature and the edge cases are mostly found.
• Fast intervals available if you pay for them, down to fifteen seconds on their higher tier, which is faster than anything Undownable sells.
• Broad alerting, including SMS and voice calls, and integrations with PagerDuty, Zapier, and the usual chat platforms.
• Status pages are available on every tier, with very high page counts on the upper tiers.

Where it starts to hurt

The friction is not the checks. It is the shape of the bill and the number of asterisks between tiers.

• Alert channels are capped on the free plan rather than all included, so the channel you actually want may be behind an upgrade.
• SMS and voice are credit metered. You buy packs, they run out, and they tend to run out during an incident.
• Extra login seats are charged individually on the lower paid tiers, so adding the second and third person to your team costs real money on top of the plan.
• Custom domains for status pages start at the first paid tier, not the free one.
• The gap between tiers is steep. Needing one more monitor, one faster interval, or one more seat can push you a whole tier up.

Side by side

Where Undownable differs

The pitch is not "more monitors for less". It is a flatter bill and a quieter pager.

• One flat price per team on Pro. No per-seat charge, no per-monitor charge, no per-status-page charge, so the whole team can have logins without a conversation about budget.
• Every alert channel on every plan, free included: email, ntfy, Telegram, Slack, Discord, and webhooks. Nothing is metered and nothing runs out.
• First class ntfy support, including your own self-hosted ntfy server with an access token, which is a real gap in most hosted monitors.
• Exactly-once alert delivery backed by a ledger, so a flapping monitor cannot double-page you or silently drop the recovery notice.
• Confirmation thresholds so a single failed check never pages anybody, and flap suppression for a monitor that will not settle.
• A degraded state distinct from down, so a warning like a near-expiry certificate is visible and alerted without being counted as an outage.
• SSL checks that verify the full chain and the hostname, with escalating warnings at 30, 14, 7, and 1 days out and an all-clear on renewal.
• JSON API checks with dot-notation assertions into the response body, so you can test that an endpoint returns the right value, not just a 200.
• Push heartbeats for cron jobs, backups, and self-hosted monitoring boxes, in the same account as your uptime checks.
• A first-party MCP server alongside the REST API, both with least-privilege tokens you can pin to a single team.
• Unlimited status pages on Pro with custom domains, and 365 days of history.

Who should stick with UptimeRobot

• You need lots of monitors for free. Fifty at no cost is a real number and Undownable does not match it.
• You need check intervals faster than one minute. Their upper tier goes to fifteen seconds; Undownable tops out at one minute.
• SMS or voice call escalation is a hard requirement. Undownable does not send SMS, and if a text message is what wakes your on-call, that decides it.
• You are already deep into their PagerDuty or Zapier wiring and the switching cost outweighs the billing annoyance.
• You want one vendor with a decade-plus operating history and that weighs heavily in your procurement process.