When a website will not load, the cause is almost always in one of three layers: the domain, the server, or the website code. Figuring out which one saves you hours and stops you from calling the wrong company. This guide walks you through pinning it down in a few minutes, using the exact clues your browser and a couple of free tools hand you, and tells you who to contact once you know.
First, rule out the boring stuff
Before you assume the worst, check whether it is only you. Open the site on your phone with Wi-Fi off, using mobile data, or in a private browsing window. If it loads there but not on your computer, the site is fine and the problem is local: your browser cache, your network, or your own DNS. Clear your cache and try again. If the site is genuinely down, it will be down everywhere, and now you know to keep digging.
The three layers, and how to tell them apart
Think of your website as a chain: the domain points to a server, and the server runs your code. A break anywhere stops the whole thing, but each break looks different.
- The domain and DNS layer is the address. If this is broken, the browser cannot even find where the site lives.
- The server and hosting layer is the building. If the address works but the building is closed, the browser finds the right place and gets no answer.
- The website code layer is what is inside. If the address and building are fine but the contents are broken, the browser connects and gets an error page instead of your site.
Read the error, because it points straight at the layer
Your browser usually tells you which layer failed, if you know how to read it:
- "Server not found," "DNS_PROBE_FINISHED_NXDOMAIN," or "this site can't be reached": a domain or DNS problem. The browser could not translate your domain into an address. Common causes are an expired domain, wrong or missing DNS records, or a recent DNS change still propagating.
- The page hangs and times out, or says "connection refused": a server problem. The address resolved, but the server did not answer. The host may be down, overloaded, or the site's IP may have changed.
- A 500 Internal Server Error, a white blank page, or a half-loaded broken layout: a code problem. The server is up and answering, but your website software hit an error, often a bad plugin, a broken update, or an expired database connection.
- A padlock warning or "your connection is not private": an SSL certificate problem, which sits between the server and code layers. The certificate expired or is misconfigured.
A real scenario
Your site stops loading and shows "DNS_PROBE_FINISHED_NXDOMAIN." That message is the giveaway: this is the domain layer, not your host or your code. You run a quick lookup and see the domain expired two days ago. No amount of calling your web developer would have fixed it, because the site itself is fine. You renew the domain at your registrar, wait for it to resolve, and the site returns. Reading the error saved you a wasted support ticket to the wrong company.
Confirm it with two free checks
- Check the domain: run a DNS or WHOIS lookup on your domain. If it shows expired, or the nameservers and records are missing or wrong, your problem is the domain layer.
- Check the server: if DNS resolves fine but nothing loads, the server is the suspect. A simple online "is it down" check, or asking someone on another network to try, confirms whether the server answers at all.
If DNS is healthy and the server answers but returns an error page, you have narrowed it to the code layer by elimination.
Who to contact for each layer
- Domain or DNS problem: your domain registrar or DNS host, whoever manages your records. They handle renewals, nameservers, and record changes.
- Server or hosting problem: your hosting provider. If the server is down, overloaded, or unreachable, only they can bring it back.
- Website code problem: your developer or whoever maintains the site. A 500 error or white screen is a software issue on a healthy server, and it usually traces to a recent change, update, or plugin.
Prevent the most common cause
The single most frequent reason a site vanishes is an expired domain on an old credit card. Turn on auto-renew, keep the payment method current, and set a calendar reminder a month before expiry. It is a five-minute safeguard against the most avoidable outage there is.
Frequently asked questions
How do I know if it is just my computer or the whole site?
Open the site on your phone with mobile data, or in a private window on another network. If it loads there, the problem is local to your device, not the website.
What does NXDOMAIN mean?
It means the domain name could not be found in DNS. Usually the domain expired, the DNS records are missing, or a recent change has not finished propagating. It is a domain-layer problem, not a server one.
The site shows a 500 error. Whose problem is that?
A 500 is a code or application problem on a working server. Contact your developer or site maintainer, and check whether a recent update or plugin change triggered it.
My site loads but shows a security warning. What is wrong?
That is almost always an expired or misconfigured SSL certificate. Your hosting provider or whoever issued the certificate can reissue or renew it.
How long does a DNS change take to fix a down site?
It depends on the record's TTL. If you lowered the TTL beforehand, minutes. If not, it can take up to 24 to 48 hours for the change to reach everyone.