How to Choose a Website Monitoring Service: A Checklist

What a website monitoring service does

A checkpoint, a server in some data center, sends your site the request a browser or an API client would send, records what comes back (status code, response time, error, page content) and compares it with what you said to expect. The check repeats every minute or every few minutes, from several locations. When a failure is confirmed, the monitor switches to down and alerts go out; when the site answers again, you get a recovery notice. Every result goes into a history that becomes uptime percentages, incident logs, response-time charts and reports.

Because the checks come from outside, they see what your visitors see: a DNS record that stopped resolving, an expired certificate, a firewall rule that blocks one country, a server that accepts connections and never answers. Your server's own logs rarely show any of these. The Google SRE book calls this black-box monitoring: it is symptom-oriented and reports that the system is not working correctly right now. The why monitor a website guide covers what takes sites down and what an unnoticed outage costs.

A monitoring service is easy to confuse with the tools next to it:

Tool	What it tells you	What it misses when the site is down
Website monitoring service	Whether the site answers correctly from outside, how fast, and since when it has not	Why the code failed inside the server
Web analytics	Who visited and what they did	The outage itself: a visitor who cannot load the page never runs the tracking script, so it shows up later as a dip in traffic
Application performance monitoring (APM)	Which function, query or service made a request slow or fail	Failures before a request reaches the app: DNS, certificates, network routes
Real user monitoring (RUM)	How fast pages load for real visitors in their browsers	Visitors who never got a page

The checklist: ten things to compare

Put each question to every service on your shortlist. The first items decide whether you can trust the alerts; the last ones decide whether the service still fits a year from now.

1. Check locations and confirmation before alerting

A single checkpoint can fail on its own, because its route to your server broke or its resolver timed out. A service that alerts on one failed check wakes you for problems your visitors never had. The SRE book describes the result: when pages come too often, people skim or ignore them and sometimes miss a real one hidden in the noise. Better services recheck a failure from other locations, alert only when several agree, and let you pick regions close to your users. The recheck strategies guide compares the common approaches.

Ask: How many locations must confirm a failure before I am alerted, and can I choose which regions check my site?

2. Check interval

The interval sets the floor on how fast you hear about an outage. At five minutes, an outage that starts just after a check runs for up to five minutes before the next check sees it, and a three-minute outage can fall between two checks and never be recorded. Confirmation adds its own delay on top. Read the fine print on "every minute" too: it can mean one check per minute in total, rotating through locations, or one per minute from each location.

Ask: What is the shortest interval on the plan I would buy, and how long does it take from the start of an outage to the alert, confirmation included?

3. Check types beyond HTTP

A 200 response tells you the server answered, not that the site works. Many real failures need a different kind of check:

• A keyword or content check catches a page that returns 200 with an error message or an empty template.
• SSL certificate and domain expiry checks can warn you weeks ahead, instead of on the morning browsers start refusing the site.
• API monitoring with assertions on the status, headers and body fields catches an endpoint that answers with the wrong data.
• Browser transaction checks log in, search, add to cart and check out the way a customer does.
• Ping and TCP port checks cover servers and services that do not speak HTTP, such as mail or a database port.
• Blacklist (DNSBL) checks tell you when your mail server's IP address or your domain lands on a spam list.

Ask: Which check types does the plan include, and are transaction checks and API assertions part of it or an extra?

4. Alert channels and escalation

An email alert sent at night gets read in the morning, and the SRE book notes that email alerts are of very limited value and tend to get overrun with noise. For outages that need someone now, look for SMS and voice calls; for team awareness, chat apps such as Slack or Telegram; for automation, webhooks into your incident tool. Escalation matters as much as the channel: if the first person does not react within a few minutes, the service should reach the next one. Also check for recovery notices and for maintenance windows that mute alerts during planned work.

Ask: Can you send SMS and voice alerts to my country, are they limited or billed per message, and can an unanswered alert escalate to a second person?

5. Status pages

During an outage your customers want to know whether the problem is on their side or yours. A status page fed by the same monitors answers that without a pile of support tickets, and people deciding whether to buy from you read its history. It has to stay up when your site does not, so it should be hosted apart from your infrastructure. The guide to what belongs on a status page covers components, incident updates and public vs private pages.

Ask: Is the status page hosted away from my servers, can it use my own domain, and does it update from the monitors automatically?

6. Reports and SLA evidence

If you promise customers an SLA, or hold your host to one, you need uptime numbers that survive a dispute. The SRE book defines an SLA as a contract that includes consequences for meeting or missing the objectives in it, so the numbers get read closely. Each incident should carry its start, end, duration, the locations that saw it and the error they got. Find out whether only confirmed downtime counts toward the percentage and whether planned maintenance can be excluded. How to calculate uptime shows the formula and what each extra nine allows.

Ask: How is the uptime percentage calculated, can I exclude maintenance windows, and can reports go out by email on a schedule?

7. API, infrastructure as code and integrations

Adding monitors by hand works for five sites. At fifty, the monitors drift away from what is deployed: new sites go unwatched and retired ones keep alerting. A documented REST API or a Terraform provider lets a new site get its monitor in the same change that ships it, and webhooks push alerts into the chat and incident tools your team already uses.

Ask: Is there a public API and a Terraform provider, and can they create and change every setting the dashboard can?

8. Managing many sites

Agencies, hosting providers and teams with dozens of sites need features a single-site owner never notices: bulk import from a list of URLs, tags or groups, bulk edits, and sub-accounts so each client logs in and sees only their own sites, contacts and reports.

Ask: Can I import a list of URLs in one step, give each client a sub-account limited to their sites, and change settings on many monitors at once?

9. Data retention and export

History answers questions that come later: when response time started creeping up, how many outages the last quarter had, whether the host met its SLA last year. Services often keep raw check results for a short time and only daily summaries after that, and retention can differ by plan.

Ask: How long do you keep raw results and incident logs, and how do I export all of it, by file or through the API?

10. Trial terms and how the price scales

The plan you start on rarely fits a year later. Pricing usually grows with the number of monitors and the check interval, and sometimes with SMS and voice credits, contacts, locations or status pages. Work out what you would pay at your current size and at three times that. Check the trial too: whether it includes every feature, whether it asks for a card, and what happens to your monitors the day it ends.

Ask: Which limit will I hit first as I add sites, what does the trial include, and will you tell me before monitoring stops?

What free tiers usually leave out

A free tier is a reasonable choice for a personal site or a side project. Free tiers are usually cut back along the same lines:

Limit	What free tiers usually do	Why it matters
Check interval	Longer intervals than paid plans	Short outages fall between checks, and long ones are found later
Monitor count	A small number of monitors	You watch the homepage and not the checkout or the API
Locations	Fewer locations, or no choice of region	Less independent confirmation, more false alarms
Alert channels	Email and chat; SMS and voice limited or paid, since every message costs the service money	Nighttime outages wait until someone reads their inbox
Check types	HTTP, ping and keyword checks; browser transactions usually paid because they cost more to run	A broken login or checkout goes unnoticed
History and reports	Shorter retention, fewer reports	No evidence for an SLA claim or a dispute with your host

Read the terms as well: some free plans are for personal or non-commercial use only. If the site earns money, look first at the interval and the alert channels, because together they decide how long an outage runs before anyone knows.

Red flags

• Checks from a single location, or no way to see which location reported a failure
• No confirmation step, so the first failed check sends the alert
• Alerts by email only
• Alerts that say "down" without the status code, the error, the location or the response time
• Uptime shown as a percentage with no incident log behind it
• Little or no history, and no export or API to take your data elsewhere
• Monitoring that runs on the same server or network as the site, so it goes down with it

How to run a fair trial

The Google SRE workbook names four attributes for judging an alerting setup: precision (the share of alerts that were real problems), recall (the share of real problems that produced an alert), detection time, and reset time (how long alerts keep firing after the problem is fixed). A one-week trial can measure all four:

1. Pick three to five URLs that match your real risk: the homepage, a page that queries the database, an API endpoint, the login or checkout page, and a test URL you can break on purpose, such as an empty file that normally returns 200.
2. Add the same URLs to every service you are comparing, with the same interval, similar regions and the alert channels you would use in production, and run them side by side in the same week.
3. Break the test URL and note the time in UTC. On nginx, add the block below to the server block and run sudo nginx -t && sudo systemctl reload nginx; remove it and reload again to recover.
4. Measure detection time (the alert minus the failure start) and the time from your fix to the recovery notice. Repeat at a few different hours, because one run proves little.
5. Count false alarms (alerts you cannot match to a real problem in your server logs) and any forced failure that never produced an alert.
6. At the end of the week, compare the incident logs with each other and with your own, and check that the uptime figure includes the outages you caused.
7. Add your real list of sites through the bulk import or the API, and send support one technical question.

location = /trial-check.html {
    return 503;
}

How HostTracker answers this checklist

HostTracker has been a website monitoring service since 2004 and checks from 300+ checkpoints in 158 cities, rechecking a failure from several locations before it alerts anyone. Checks run as often as every minute, and alerts go out by email, SMS, voice call, Slack, Telegram and more, with escalation rules that decide who hears next. Each monitor keeps its own history, with weekly or monthly uptime reports and public status pages, and bulk import, tags, sub-accounts, a REST API and a Terraform provider handle large numbers of sites. The free HTTP check shows what a checkpoint gets from your site before you set anything up.

Frequently asked questions

What is the difference between website monitoring and uptime monitoring?

Uptime monitoring answers one question: is the site reachable and answering? Website monitoring includes that and adds checks on whether the site works: page content, response time, certificates and domains, transactions and APIs. Most uptime monitoring services offer some of these, so the terms get used interchangeably. Compare the check types, not the label.

Is website monitoring software different from a monitoring service?

Software usually means a tool you install and run yourself, while a service runs the checks on the provider's network. Self-hosted software checks from wherever you install it, so it sees one network unless you deploy probes in several places, and it can go down with the network it watches. A hosted service checks from its own locations and can still alert you when your whole infrastructure is offline.

How many check locations do I need?

At least three, so a failure can be confirmed or overruled by majority, in or near the regions your visitors come from. More locations help most when your audience is spread across continents or the site sits behind a CDN, where one region can fail while the rest are fine.

My host already monitors its servers. Do I still need a monitoring service?

Usually yes. The host watches its own hardware and network, and its alerts go to its own staff. It does not see an expired domain, a broken DNS record, a plugin error that returns a blank page or a certificate you forgot to renew, and it may not tell you about a short outage it fixed on its own. An outside service reports what your visitors experienced, and the alert comes to you.

Sources and further reading

• Google SRE book, Monitoring Distributed Systems: black-box vs white-box monitoring, symptoms vs causes, alert noise and the limits of email alerts.
• Google SRE workbook, Alerting on SLOs: precision, recall, detection time and reset time as the measures of an alerting setup.
• Google SRE book, Service Level Objectives: how SLIs, SLOs and SLAs differ, and why an SLA needs an objective measurement behind it.