[1,048 words, 6 minute read time]
If you run a website that customers, readers, or leads depend on, downtime isn’t just “a technical issue.” It’s a business problem that can cost you sales, credibility, and sleep.
Uptime monitoring is the simplest way to protect against that: it continuously checks your website and alerts you when something stops working—so you find out from your monitoring tool, not from your customers.
Think of it as an insurance policy for your revenue and reputation: you hope you never need it, but when you do, you’ll be glad it’s there.
For a full hub-style overview and setup roadmap, see the complete guide.
What “uptime” means (availability vs reliability)
You’ll hear “uptime” used as a catch-all, but there are two related concepts:
Availability (is it reachable right now?)
Availability is the percentage of time your website can be reached and responds successfully.
If your site is available, users can load it and interact with it at least at a basic level.
Reliability (does it keep working under real conditions?)
Reliability is about whether your site continues to work consistently, especially in the flows that matter:
- login
- checkout
- form submissions
- critical API calls
A site can be “available” (the homepage loads) but not “reliable” (checkout fails). That’s why mature setups don’t just monitor the homepage—they monitor what users need to succeed.
Why uptime monitoring matters (even for “small” sites)
Most website owners underestimate downtime because they think of it as rare and obvious. In reality, downtime is often:
- partial (only certain pages or regions fail)
- intermittent (it flaps—up/down)
- invisible to you (but very visible to users)
Quick downtime cost calculator (simple and useful)
You don’t need perfect math—just a reality check.
Estimated downtime cost per hour ≈
(Revenue per hour) + (Leads per hour × value per lead) + (Support cost per hour) + reputation risk
To estimate quickly:
- Revenue per hour = monthly revenue ÷ 30 ÷ 24
- Leads per hour = monthly leads ÷ 30 ÷ 24
Even if you’re not ecommerce, downtime can still cost:
- missed bookings
- failed form submissions
- lost ad spend
- churn from frustrated users
Common causes of website downtime
Downtime rarely has a single cause. Here are the usual suspects:
Hosting / infrastructure issues
- server outages
- resource exhaustion (CPU/RAM)
- storage full
- network connectivity problems
- load balancer failures
DNS problems
- domain not resolving
- bad DNS records
- propagation issues after changes
- domain expiration
DNS issues are notorious because the site can look “fine” from one network and broken from another.
Application errors
- 500/502/503 errors
- broken deployments
- database connection failures
- timeouts from slow backend services
- caching misconfigurations
Security and bot protection
- WAF rules blocking legitimate traffic (or your monitors)
- DDoS mitigation triggering blocks
- rate limiting
- certificate/TLS issues
Third-party dependencies
Modern websites are ecosystems. If one dependency fails, your site can fail:
- payment processors
- login/auth providers
- analytics/tag managers (yes, sometimes these can break pages)
- third-party APIs
What monitors actually test (and what they don’t)
An uptime monitor is not a human browsing your site. It’s an automated check that asks a specific question, such as:
- “Does this URL respond successfully over HTTPS?” (HTTP monitor)
- “Does this page contain the expected text?” (keyword check)
- “Does this server respond to a ping?” (ping monitor)
- “Is this service reachable on a port?” (port monitor)
What uptime monitoring is good at
- catching outages quickly
- detecting patterns (flaky hosting, recurring incidents)
- proving uptime history (useful for stakeholders and agencies)
- reducing “we only found out because a customer complained”
What uptime monitoring is not good at (by itself)
- diagnosing the root cause (it tells you something broke, not why)
- guaranteeing a good user experience
- replacing performance monitoring, security tools, or QA tests
That said, uptime monitoring is the foundation—and you can add sophistication over time.
Starter setup: 2 monitors, 2 alerts, 1 runbook
If you do nothing else, do this. It’s the simplest setup that catches most real-world incidents without overwhelming you.
The “starter stack” checklist
✅ 2 monitors
- Homepage (HTTP monitor)
- answers: “Is the site reachable?”
- Key page or /health endpoint (HTTP or keyword monitor)
- answers: “Is the important thing working?”
✅ 2 alerts
- Primary alert (email + Slack/Teams or email + SMS)
- Escalation alert if downtime persists 10–15 minutes (SMS/push or a backup person)
✅ 1 runbook
A one-page checklist that says:
- who responds
- where to check first (hosting, DNS, deploys)
- how to communicate
- how to escalate
If you want a simple, practical incident workflow, see the alerting playbook.
Recommended default settings (safe for most sites)
- Check interval: every 5 minutes
- Timeout: 10 seconds
- Retries: 2 (confirm before alerting)
- Regions: start with 1–2 locations
“Which tool should I use?”
A beginner-friendly path is to follow a step-by-step setup guide in a tool like UptimeRobot. Start here: UptimeRobot setup.
When to level up (multi-step checks, APIs, status pages)
Once your website becomes important enough that downtime is expensive, you should level up beyond “homepage is up.”
Level up if…
- users log in and do real work (SaaS, membership, dashboards)
- checkout or payment is critical (ecommerce)
- your frontend depends on APIs (many sites do)
- you have customers who need transparency during incidents
What to add first (in order)
- Keyword checks on your most important page (confirms real content, not just “200 OK”)
- Multi-step monitoring for login/checkout (confirms key journeys work)
- API monitoring for critical endpoints (auth + payload validation)
- SSL and DNS monitoring (prevents avoidable “sudden outage” scenarios)
- Status page (for customer-facing communication and trust)
These upgrades are covered in the advanced hub: complete guide (and the advanced monitoring pillar if you’re ready).
FAQ: quick answers non-technical stakeholders ask
“If my site is down, won’t I notice?”
Not always. Outages can be regional, intermittent, or specific to certain pages (login/checkout).
“Is uptime monitoring hard?”
No. A starter setup takes ~10–15 minutes. The real work is deciding what’s most important to monitor.
“Will monitoring prevent downtime?”
Monitoring doesn’t prevent outages—but it reduces their impact by detecting them faster, so you can respond quickly.
Start here: homepage + /health (or your key page)
If you’re setting this up today, do this:
- Create an HTTP monitor for your homepage
- Create a second monitor for /health (if you have it) or your most important page
- Turn on email alerts and one second alert channel (Slack/Teams or SMS)
- Test one alert so you trust it
CTA: Start with homepage + /health (or your key page)—then expand once you’ve proven the basics work.