First, the reassuring bit. When a website stops working, the content is almost always still there. It's rarely deleted, and most of the time the cause is one specific thing that can be found and put right. The hard part is working out which thing, so here's how I'd go about it, in the order I'd do it.
First, is it just you?
These checks take a few minutes and rule out the most common false alarms.
- Load the site on your phone using mobile data rather than wifi. If it works there, the problem is probably your connection or something saved in your browser.
- Check whether the whole site is affected, or only certain pages or the admin area.
- Look at your hosting company's status page, or any recent emails from them. Maintenance notices naming web hosting or database services are the ones to look for.
- Make sure your hosting and your domain name are both paid up and haven't expired. A failed card payment looks exactly like an outage from the outside.
- Take a screenshot of whatever you can see, and note roughly when it started. Both will save a lot of time later.
What are you seeing?
The message on the screen narrows down the cause more than anything else, so find the closest match below.
error
There has been a critical error on this website
Something in the site's code, usually a plugin or theme, has failed badly enough that WordPress stopped altogether. It's often fixable quickly once someone looks at the error log. Check your inbox for an email from WordPress headed "Your Site is Experiencing a Technical Issue", which can get you back in. Full guide: the critical error explained.
error
Error establishing a database connection
WordPress keeps everything you've written in a database, and this means it can't reach it. That's often on the hosting side, such as a database server being down or under maintenance, so check your host's status page first. It can also follow a move or a change of login details. If the status looks fine, ask your host whether your database is running. Full guide: what to ask your host.
screen
A blank white page
This is the older, less dramatic cousin of the critical error message and has much the same causes: a plugin or theme that has failed, or a site running out of the memory your host allows. The same steps apply.
update
A maintenance message that never goes away
WordPress shows "Briefly unavailable for scheduled maintenance" while it installs updates, and it should clear within a minute or two. If it's still there an hour later, an update was probably interrupted and left a small temporary file behind. It's usually a quick fix for someone with access to the site's files.
error
A 500 or 503 error
Both come from the server rather than the website itself. A 503 can be a temporary overload, and a 500 can be a fault in the site or its setup. Check your host's status page, and ask them for the error log for your site around the time it began.
issue
The site can't be reached, or your host's default page appears
That points at the domain, the DNS settings or the hosting account rather than WordPress. Check that your domain hasn't expired and that your hosting is paid up, and ask whoever manages your domain whether anything was changed recently.
problem
You can't log in
Try the "Lost your password" link on the login page first. If the reset email never arrives, the site's email may be broken, or the admin address may belong to someone else, such as a developer who built it years ago. Someone with access to your hosting can reset it from there. Please don't send your password over email.
hack
Strange redirects, or Google says the site is unsafe
That's a sign the site may have been hacked. Don't keep trying things yourself, as that can make a cleanup harder, and get someone to look at it promptly. For what's usually involved, see a neglected site and the security basics.
site
It's working, just very slow
That's a different problem with a different set of causes. See what's slowing your site down.
What to have ready when you ask for help
Your website address, the name of your hosting company, a screenshot of what you're seeing, roughly when it started and anything that changed beforehand, such as an update, a new plugin or an email from your host. Knowing who holds the logins helps too.
If I need access to look properly, I'll ask you to add me as a separate user or set up a temporary login, so your own password never has to change hands. I'll look first, tell you what I find and what I'd recommend, and nothing gets changed until you've agreed to it.
Site down and want a second pair of eyes? Email hello@wpbase.co.uk with your website address and what you can see, or ring +44 7440 018091. I'll tell you in plain English what I think is happening and what your options are.
Once it's back up, the sensible next step is making it less likely to happen again. Regular updates, off-site backups and someone watching for downtime are what turn a long outage into a short one, and they're exactly what a maintenance plan covers.