This guide gives you four quick checks, then explains what each common error message means and which fix to try first. It is written for owners and marketers, not developers, so every step says what to look at and what the result tells you.
Step 1: Check whether it is just you
Most reports of a site being down turn out to be a local problem. Work through these in order, and stop at the first one that explains it.
Open the site on your phone using mobile data, with Wi-Fi switched off. If it loads there, the problem is on your home or office network, your browser, or a saved copy of the page. Try a private window as well, because an old cached page or a browser extension can break a site on one device only.
Ask someone in another place to open it, or run the address through a free "is it down" checker. These tools request your page from their own servers, so they show how the site looks from outside your network. If the checker says the site is up and you cannot reach it, the fault is yours to find locally: restart the router, switch off a VPN, or try another network.
If your phone on mobile data and an outside checker both fail, the site really is down. Carry on to the next steps.
Step 2: Read the error message
The message on the screen narrows the cause a lot. Write it down exactly, including any number, because your host will ask for it.
A 500 Internal Server Error means the server tried to build the page and something in the site code broke. On WordPress and similar systems this is usually a plugin, a theme or a bad update. A 502 Bad Gateway or 504 Gateway Timeout means one server in the chain, such as a proxy or CDN, could not get an answer from the server behind it. A 503 Service Unavailable means the server is overloaded or switched to maintenance mode. A 404 on the home page itself usually points to a missing file or a broken redirect rule after a change.
Browser messages that talk about the connection rather than a number point elsewhere. "This site can't be reached" with a DNS message means the domain is not pointing at a server, which happens when a domain expires, a nameserver is changed by mistake or a DNS record is deleted. A certificate warning with words like "Your connection is not private" means the SSL certificate has expired or does not match the address. The site may be fine behind the warning, but visitors will not click through it.
Step 3: The fixes to try, in order of likelihood
Check your hosting provider's status page first. If there is an outage, nothing on your side will help and the work is waiting. Then check that the domain has not expired and that the hosting account is paid up. A lapsed card is one of the most common causes of a site that vanishes overnight, and it is the fastest to fix.
Next, think about what changed in the last day or two. Did anyone update a plugin, install a theme, edit a redirect, change DNS or move the site? If yes, undo that change first. On most hosts you can switch off a plugin from the file manager or restore the last backup in a few clicks. Fixing the change you made yesterday is far quicker than diagnosing from scratch.
If you use a CDN or caching layer, purge the cache and test again, because an old error page can stay in the cache after the real problem is solved. Check the SSL certificate's expiry date in your host's control panel and renew it if it has lapsed.
Still down? Contact your host with the exact message, the time it started and what changed. A clear report such as "500 error from 9:40, after updating the shop plugin" gets a useful answer instead of a request for more details.
When the site is slow rather than down
A page that takes ten seconds to load costs you visitors almost as surely as an error does, and it is harder to notice because the site technically works. Common causes are a traffic spike on cheap hosting, an oversized image added to the home page, or a script from another service that is slow to respond. Run the page through a speed test and look at what loads slowest. Our guide to reading speed test results explains which numbers to focus on.
How to find out before your customers do
The worst way to learn your site is down is a customer message. The best way is an automatic check that tells you within minutes. For that, use a dedicated uptime monitoring service. Many offer a free plan that checks every few minutes and sends an email or text. Set the alerts to go to a shared inbox or more than one person, so a holiday does not mean a missed warning.
Be clear about what each kind of tool does. An uptime service answers one question quickly: is the site responding? Dynamic Growth monitoring answers a different one: is the page that responds still healthy? It reads your public pages once a week and compares the result with the last check, flagging things like a missing tracking tag, a certificate close to expiry, an accidental noindex instruction or a slower page. It will not catch a ten minute outage on a Tuesday afternoon, so the two work best together.
Whichever you choose, write down who is told, who fixes it and where the host's login details are kept. When a site goes down at 7 a.m., that note saves an hour.
A short checklist to keep
Check it on mobile data and with an outside checker. Read and note the exact error. Look at the host status page, the domain expiry date and the payment on file. Undo the most recent change. Purge the cache. Contact the host with specifics. Afterwards, set up an uptime alert and a weekly quality check so you hear about the next problem first.
Frequently asked questions
Why does my website say "this site can't be reached"?
That message usually means your browser could not connect to a server for the address. The causes are a domain that expired or lost its DNS settings, a server that is switched off or overloaded, or a local network problem. Test on mobile data and with an outside checker to find out which.
How do I check if a website is down for everyone?
Open it on a phone using mobile data, ask someone elsewhere to try it, or use a free is-it-down checker that requests the page from its own servers. If those all fail, the site is down for everyone. If they work, the problem is on your own network or device.
How long do website outages usually last?
It depends on the cause. A cache or plugin problem you can undo may take minutes. A hosting outage depends on your provider. An expired domain or certificate lasts until it is renewed, and a domain renewal can take hours to fully take effect.
Does website downtime hurt SEO?
Short, rare outages are normally harmless. Search engines expect an occasional problem and return later. Days of repeated server errors can cause pages to be crawled less or dropped from results, so fix long outages quickly and use a temporary 503 response, not a 404, during planned maintenance.
Can Dynamic Growth tell me when my site goes down?
Not within minutes. It is a weekly quality check, not an uptime service. It records whether your site answered during each check and highlights changes since the last one, which makes it a good partner for a dedicated uptime alert.