What is website monitoring?
Website monitoring is the practice of checking your site automatically and continuously, from outside your own infrastructure, to confirm that it is reachable, responds quickly, serves a valid certificate and resolves correctly in DNS. When a check fails, the monitoring tool alerts the right people so they can fix the problem while it is still small.
Key website monitoring metrics
- Uptime: the share of checks in which your site responded successfully, usually shown as a percentage over 30 or 90 days
- Response time: how long the server takes to answer a request, including time to first byte (TTFB)
- HTTP status codes: whether pages return 200 OK or errors such as 404, 500 or 503 (see our HTTP status codes guide)
- Core Web Vitals: Largest Contentful Paint (LCP), Interaction to Next Paint (INP) and Cumulative Layout Shift (CLS)
- Certificate and DNS health: days until your SSL/TLS certificate expires and whether DNS records still point where they should
Types of website monitoring
No single check covers everything. Most teams combine several types of website monitoring, each answering a different question.
Uptime monitoring
Is the site reachable? An uptime check requests a URL at a fixed interval and verifies that it answers with the expected status code. It is the foundation of any setup and the fastest way to learn about an outage.
Performance monitoring
Is the site fast enough? Performance monitoring tracks load times, Google Lighthouse scores and Core Web Vitals so you can spot regressions after a deploy. Our Lighthouse performance monitoring guide goes deeper.
SSL certificate monitoring
Is the connection trusted? Certificate checks warn you before a certificate expires or breaks, so visitors never see a browser security warning. Read our SSL certificate monitoring guide.
DNS monitoring
Does your domain still resolve correctly? DNS monitoring watches records such as A, MX and NS for failures and unexpected changes, which can take down a site or email even when the server is healthy.
Functional (transaction) monitoring
Do key journeys work? Scripted browser checks log in, search or complete a checkout to confirm that critical flows work end to end, not just that the homepage loads.
Synthetic monitoring vs real user monitoring
Website monitoring data comes from two sources. Most teams start with synthetic checks and add real user data as traffic grows.
Synthetic monitoring
Automated checks run on a schedule from monitoring servers, so they work even at 3 a.m. when nobody is visiting. They produce consistent, comparable measurements and catch outages before real users do.
Real user monitoring (RUM)
A script in your pages collects timings from actual visitors on real devices, browsers and networks. RUM shows how the site performs in the field, but only for pages people are visiting.
API monitoring
If your frontend depends on APIs, monitor their endpoints directly. A page can return 200 OK while the API behind it fails, leaving users with empty or broken screens.
How to set up website monitoring
A useful setup takes an afternoon, not a project. Work through these steps in order.
- 1
List what you need to monitor
Start with the pages and endpoints that earn or lose money: the homepage, login, signup or checkout, and any public API. Add the domains and certificates they depend on.
- 2
Choose check intervals
The check interval limits how quickly you can detect an outage. Business-critical pages justify checks every minute or more often; low-traffic pages can be checked less frequently.
- 3
Route alerts to the right place
Send alerts where your team already works, such as email, a Slack channel or a webhook into your incident tool. Confirm a failure before alerting so a single dropped request does not wake anyone up. Our Slack webhook setup guide shows how to connect Slack.
- 4
Define who responds and how
Decide who is on call, what the first diagnostic steps are and when to escalate. A public status page lets you keep customers informed without answering every support ticket individually.
- 5
Review and tune regularly
After each incident, check whether monitoring caught it quickly and whether the alerts were actionable. Adjust thresholds, add missing checks and remove noisy ones.
Website monitoring best practices
These habits keep your monitoring accurate and your alerts worth reading.
- Monitor from outside your own network so you see what visitors see
- Check the pages that matter, not just the homepage
- Base alert thresholds on your normal response times so alerts fire on real problems, not minor fluctuations
- Track performance over time and compare results before and after each release
- Monitor certificates and DNS alongside uptime, because they cause outages that uptime checks alone do not explain
- Keep a short written runbook next to each alert
Common website monitoring mistakes
Most monitoring failures are not technical. They come from gaps in coverage and alerting.
- Monitoring only the homepage while login, checkout or the API fails silently
- Sending every alert to a shared inbox that nobody watches
- Alerting on a single failed check, which trains the team to ignore alerts
- Forgetting subdomains, redirects and third-party dependencies
- Never testing whether alerts actually arrive
- Measuring uptime but not speed, even though a very slow page loses visitors much like an outage
Website monitoring with nanokoi
nanokoi brings the checks described above into one dashboard. You can start on the Free plan with up to 5 URLs.
Uptime and SSL on every plan
Every plan includes uptime monitoring and SSL certificate monitoring. Check intervals range from 5 minutes on Free to 30 seconds on Professional, with custom intervals on Enterprise.
Performance and Core Web Vitals
Google Lighthouse performance monitoring and Core Web Vitals tracking, plus AI-generated optimisation reports that explain what to fix first.
DNS monitoring
Watch A, AAAA, CNAME, MX, NS, TXT and SRV records for failures and changes. See how DNS monitoring works.
Alerts, status pages and API
Alerts by email, Slack or webhook, public SLA status pages, data export as CSV, JSON or XML, and a REST API on paid plans.
Website monitoring FAQ
What is website monitoring?
Website monitoring is the automated, continuous checking of a website's availability, speed, certificate and DNS health from outside your infrastructure, with alerts when something breaks.
How often should I check my website?
It depends on how costly downtime is. For revenue-critical sites, checks every minute or more often keep detection time short; for low-traffic sites, every five minutes is often enough. On nanokoi, intervals range from 5 minutes (Free) to 30 seconds (Professional).
What is the difference between uptime monitoring and website monitoring?
Uptime monitoring answers one question: is the site reachable? Website monitoring is broader and also covers performance, Core Web Vitals, SSL certificates, DNS and key user journeys.
Does website monitoring help SEO?
Indirectly. Monitoring does not change rankings by itself, but it helps you fix outages, slow pages and certificate errors quickly. Google's Search Central documentation states that Core Web Vitals are used by its ranking systems, and pages that fail to load cannot be crawled.
Can I monitor my website for free?
Yes. nanokoi's Free plan monitors up to 5 URLs with 5-minute checks, including uptime and SSL certificate monitoring, and no credit card is required.
Start monitoring your website
Set up uptime, performance and SSL checks in a few minutes. The Free plan covers up to 5 URLs.
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