Free Uptime Monitoring Tools Compared: What to Check Before You Pick

Free uptime monitoring is a crowded field, and the headline numbers hide the details that matter. This page lists several well-known free monitors, including our own, gives you criteria for choosing, and is honest about where we are small. SiteDownCheck is a new service with a deliberately modest free plan, so in raw capacity we are not the biggest.

All competitor limits below are what each official page said at the time of writing (October 2026). Free plans change often, so check their pricing page before you commit. Where we could not verify something on an official page, we say so.

Selection criteria that actually matter

Before looking at any list, decide what you need:

1. How many things must be watched. A blog, a shop and an API is three monitors. A freelancer with 25 client sites is a different problem.
2. How fast you must know. A 5-minute interval means an outage can run up to roughly five minutes before the first check sees it. How often should you monitor a website explains the trade-off.
3. Where checks run from. One location cannot tell a regional network issue from a real outage. Multiple locations reduce false alarms.
4. How failures are confirmed. Does one failed check alert, or is the failure re-checked first? This decides how noisy your inbox gets.
5. What else it watches. SSL and domain expiry, keyword or JSON checks, heartbeat monitors for cron jobs.
6. Alert channels. Email is universal. Slack, Discord, webhooks, SMS and phone calls vary, and SMS is often paid.
7. Public status page. Some free plans include one, some do not.
8. What happens when you outgrow it. Is there a sensible paid tier, and is the free plan permanent or a trial?

The tools, at a glance

Short notes on each

UptimeRobot is the default answer if you simply need many free monitors. Fifty at 5-minute intervals covers most personal portfolios. See our UptimeRobot comparison.

HetrixTools adds blacklist monitoring and server agents to uptime, which suits sysadmins and hosting providers. See the HetrixTools comparison.

Hyperping has a clean free plan with 20 monitors and a status page, with team seats on paid tiers.

StatusCake gives ten uptime monitors and a sample of other monitor types on the free plan. See the StatusCake comparison.

Better Stack is generous on monitors and heartbeats and sits inside a platform with on-call and logs, which is either a benefit or overkill. See the Better Stack comparison.

Instatus is known for status pages. Its free plan listed monitors too, but check what you get before relying on it for alerting.

updown.io is the odd one out: pay per check, with frequency down to 15 seconds. See the updown.io comparison.

Site24x7 is a suite; the free plan is a way into a much bigger product. See the Site24x7 comparison.

Where SiteDownCheck fits

We are the smallest free plan on this list: three monitors. What we try to do well within that limit:

• Confirm a failure before alerting, so one bad packet does not wake you.
• Define "down" clearly: connection failures, timeouts, certificate errors and HTTP 5xx, 404 and 410 are down; 401, 403 and 429 count as up with restricted access.
• Include keyword checks and JSON path checks so a 200 with a broken page still fails.
• Warn about SSL and domain expiry at 30, 14, 7 and 1 days, plus DNS and certificate change alerts.
• Support maintenance windows, a public status page with 30-day history, badges and an emailed monthly report.
• Offer heartbeat monitoring for cron jobs, which counts toward the three monitors.

What we do not do: multi-location checks on the free plan (checks run from a single default location), SMS or phone alerts, checks faster than 5 minutes, scripted browser monitoring, or server agents. Pro is planned, with no price or date.

Which one should you pick?

• Many sites, zero budget: a large free tier such as UptimeRobot, HetrixTools or Hyperping, depending on what else you need.
• Sysadmin with servers and mail: HetrixTools for blacklist and server monitoring.
• A few critical URLs and you want expiry and content checks bundled: SiteDownCheck is a reasonable fit.
• Engineering team needing on-call: a platform such as Better Stack, or a suite.
• You want to control cost by usage: updown.io.
• Maximum reliability for little money: use two free services from different networks on the same critical URL.

A note on reading free plans

Free tiers are marketing as well as products, so be skeptical of any single number. Check the interval, whether alerts for SMS are included, whether the status page is branded, how long history is kept and whether commercial use is allowed. Read the terms for your use case. And remember that no monitor makes your site more reliable; it only tells you sooner. Pair it with a plan for reducing false alerts and a calm status page process.

Next steps

• Start a free monitor and compare it to your current one for a week.
• Learn what uptime percentages mean.
• Add domain expiry watch.
• Read uptime monitoring for small business.
• Compare status page tools.

FAQ

Which free uptime monitor has the most monitors?

At the time of writing, UptimeRobot listed 50 on its free plan, the largest of the tools we checked. Confirm on their pricing page.

Is 5-minute checking good enough?

For most small sites, yes. You will learn about an outage within about five minutes plus confirmation time. If minutes cost you money, look at paid plans with faster checks.

Can I use two free monitors on the same site?

Yes, and it is a good practice for important URLs. Different networks help separate real outages from local network problems.

Is SiteDownCheck free forever?

The free plan has no trial period or credit card. Pro is planned, and our pricing page says the free plan stays when it launches.

Opinions here are our own; verify vendor details yourself. See our editorial policy and disclaimer.