Here's a quiet fact that affects a huge slice of the web agency world: UptimeRobot's free plan is not allowed for commercial use, and it hasn't been since a terms-of-service change in November 2024.
If you're a freelancer or agency monitoring client websites on UptimeRobot's free tier, and given that the free tier offers 50 monitors, an enormous number of shops do exactly this, you are, in all likelihood, using the product outside its terms. Most people in this position have no idea. The monitors kept working, no email demanded an upgrade, and nobody rereads a ToS for a free tool.
Disclosure before we go further: I run Sentinel, a competing monitoring service. I'll pitch it at the end, clearly labeled. Everything before that is the situation as it stands, including options that don't involve us.
What the terms actually say
In November 2024, UptimeRobot updated its terms of service to restrict the free plan to personal, non-commercial use. Paid plans are the sanctioned route for any business usage. Don't take my paraphrase as gospel: the authoritative text is UptimeRobot's own Terms of Service, and you should read the current version yourself, because terms change and this post can't update itself the moment they do.
But the shape of it is simple: free plan = personal projects. Business activity = paid plan.
"Does monitoring client sites really count as commercial use?"
Almost certainly yes. Ask yourself:
- Do you charge clients for a care plan, maintenance retainer, or hosting package that includes "we monitor your site"? That's a paid service you're delivering with a free tool.
- Do your proposals or contracts mention uptime monitoring as a deliverable? You're billing for it.
- Is the site being monitored a business's site, watched by you as their vendor? Hard to characterize that as personal use.
The gray areas are narrow: your own portfolio site, a side project, a nonprofit you volunteer for. A roster of 30 client sites under an agency account is not a gray area.
"Nobody's enforcing it, so who cares?"
Maybe nothing happens. Companies often change terms and enforce them lazily or never. But you're carrying three risks, and only one of them is about enforcement:
- Enforcement risk. UptimeRobot can suspend accounts that violate terms. If that happens, every client monitor you run goes dark at once, and you find out about it at the worst possible time, because the thing that would have told you is the thing that got suspended.
- Professional risk. You're charging clients for a monitoring service delivered in violation of the provider's terms. If a client with a real SLA ever digs into how their uptime is monitored (during a dispute, say), "a free tool we weren't licensed to use commercially" is a bad sentence to say out loud.
- The it-was-always-borrowed-time problem. Freshping users learned this in March 2026 when Freshworks shut it down entirely. Free tiers of commercial products are marketing expenses, and marketing expenses get cut. Building paid client deliverables on top of one is a structural risk, not just a legal one.
None of this makes UptimeRobot a villain. Fifty free monitors was an extraordinarily generous tier, and asking businesses to pay for business use is completely reasonable. The problem isn't them charging. It's the thousands of agencies who never got the memo and are now unknowingly out of compliance.
Your three options
1. Pay UptimeRobot
The most direct fix: upgrade to a paid plan and keep your setup exactly as it is. Zero migration cost, a mature product you already know.
One thing to model before you commit: UptimeRobot charges $15 per seat per month. Solo, that's manageable. But if your PM needs to see monitor status, your developer needs to acknowledge alerts, and your support person needs the dashboard, a 5-person team is $75/month in seats alone, on top of the plan. Price the roster you'll have in a year, not the one you have today.
2. Self-host Uptime Kuma
Uptime Kuma is free, open source, and good. If you're comfortable running a Docker container and maintaining it, your ToS problem disappears entirely: you can't violate the terms of software you host yourself.
The trade-off: your monitoring now runs from a single server that you maintain, and when that server has a bad day, your monitoring silently dies with it. You also inherit updates, backups, and the ongoing time cost. For client work with real accountability, be honest about whether you want your alerting infrastructure to be a hobby-grade responsibility.
3. Switch to a tool that's licensed for what you're doing
The clean fix is a monitoring service whose plan you're actually entitled to use for client work, free or paid, hosted, with terms that match reality. HetrixTools has a usable free tier without the commercial-use restriction. Several paid tools (Oh Dear, Better Stack, Pingdom, StatusCake, us) are all legitimately available for agency use; compare on how their pricing treats a growing multi-client roster, because that's where the models differ wildly. Our guide to UptimeRobot alternatives walks through the main candidates by use case.
The Sentinel pitch (clearly labeled)
Here it is. Sentinel is built for precisely the person this ToS change caught out: someone responsible for a roster of client sites.
- Every endpoint gets uptime, SSL expiry, DNS change, and domain expiry monitoring on any paid plan (the free tier covers uptime and SSL). One line item covers the four ways client sites actually break.
- No per-seat fees. Your whole team logs in; the bill doesn't notice. (Business at $59/month has unlimited seats, 300 endpoints, 30-second checks, and status pages on your own domain.)
- Flat, quotable pricing. Starter $14/month for 25 endpoints; Pro $29/month for 100. A 50-site roster costs $29, a number you can write into a care-plan line item without wincing.
- Free plan, honestly scoped: 10 monitors, 5-minute checks, no card, and yes, you're allowed to use it for client sites. It's not a bait tier; it's a small tier.
We're not the cheapest option and our free tier is smaller than UptimeRobot's was. What you're buying is fit: monitoring that's designed, priced, and licensed for the job of watching other people's websites for money.
If that's your job, start free and move your top 10 client sites over today. The rest can follow once you've seen it work.
And if you stay with UptimeRobot, genuinely fine. Just move to a paid plan and get yourself compliant. The worst option is the one most agencies are currently on: the free plan, out of terms, one policy-enforcement sweep away from losing every monitor at once.