How to know when your website is slow or down

A customer calls: "your website is down." You open it on your phone and... it works. Or it does not, and nobody knows since when. Every hour with the site down or very slow means lost sales, contact forms that never arrived and paid ads sending people to a broken page.

The good news: you can find out before your customers do, without opening the site every few minutes.

Why you are the last to know

• Browser cache: your browser has already saved much of the site. It may even show a saved version while the server is having problems.
• Always from the same place: you visit from the same city, network and device. A problem that affects another region, or only mobile users, goes unnoticed.
• Slowness creeps in: a plugin update here, a new script there, and the site gets 2 seconds slower over three months. Nobody notices until sales drop.
• After hours: outages at night or over the weekend are only discovered on Monday.

What can take a site down or slow it down

• Overloaded or unstable hosting.
• An expired domain (auto-renewal on an expired credit card is a classic).
• An expired SSL certificate, which makes the browser show a scary warning.
• A plugin, theme or system update that broke something.
• Attacks and unexpected traffic spikes.
• Third-party scripts (chat, ads, pixels) that started to lag.

The two types of monitoring

Uptime monitoring

A bot visits your site every few minutes and checks that it responds. If it does not, you get an alert, usually by email, SMS or app.

• Answers: Is the site up? When did it go down? How long was it out?
• Does not answer: whether the site is slow or offers a poor experience.

Performance monitoring

A full speed test runs at regular intervals (daily, for example) and keeps a history.

• Answers: Is the site getting slower? Since when? What changed?
• Does not answer: short outages between one test and the next.

The two complement each other: one warns you of emergencies, the other shows health over time.

There is also real user monitoring (RUM), which measures the experience of actual visitors. It is the most complete option, but it requires installing code on the site and is mostly used by larger companies. Google's field data in Search Console is a free, simplified version of it.

What to monitor

You do not need to monitor every page. Pick the ones that matter most to the business:

1. The homepage.
2. Pages that receive paid traffic (ad landing pages).
3. Pages that bring in money or leads: main product, cart, quote request form, booking.
4. The most visited pages, according to Google Analytics.

How to set up good alerts

• Send them to someone who can act: the person responsible for the site, the agency or the developer, not an inbox nobody reads.
• Avoid false alarms: good monitors confirm an outage from more than one location before alerting.
• Alert when it comes back, too: knowing the problem is resolved is as important as knowing it started.
• Track slowness as a trend: an alert for every slower test becomes noise; a consistent decline over several days deserves attention.

What to do when an alert arrives

A simple plan, in order:

1. Confirm from another network: open the site on your phone's mobile data, without Wi-Fi, or ask someone else.
2. Read the error message: "server not found" suggests a domain or DNS issue; a 500 or 503 error suggests a server or site problem; a security warning suggests an expired certificate.
3. Check your host's status page and open a support ticket if needed.
4. Remember what changed recently: an update, a new plugin, a DNS change. Undoing the last change fixes many cases.
5. Check domain and certificate: expiration dates at your domain registrar and in your hosting dashboard.
6. Tell whoever needs to know: sales, customer support and, if the outage is long, pause your ads so you do not pay for clicks to a page that is down.

Monitoring tools

• Uptime services (such as UptimeRobot, Better Stack and Pingdom): many have free plans with limits and make a great first layer.
• Google Search Console: flags indexing problems and shows real-user Core Web Vitals, but with a delay of several days.
• Google Analytics: a sudden drop in visits can reveal a problem, but only after the damage is done.
• Teste de Performance: with an account, you choose your key pages and they are tested automatically, with a history chart, uptime checks and email alerts when a page goes down or performance drops. Everything explained in plain language, on plans built to fit.

Summary

• You will not notice on your own: automate it.
• Combine uptime (is it up?) and performance (is it fast?).
• Monitor the pages that drive results.
• Have a plan ready for when the alert arrives.

Want to know how your site is doing right now? A free test shows speed, SEO and AI readiness in about a minute. And if you want to compare options before deciding, see our comparison of speed test tools.