A family-run garden centre outside Cavan reprinted last spring's flyer for the summer season. Same design, same QR code, thousands of copies handed out at the local mart and tucked into deliveries. The code pointed at a seasonal offers page. Trouble was, someone had tidied up the website over the winter and deleted that page. So every customer who scanned the code landed on a bare grey screen that said "Not Found" and nothing else. No menu, no search, no obvious way back to the shop. Most of them did the only thing that screen invites. They closed the tab.

Nobody rang to complain. That is the part that should worry you. A broken link does not trigger an alert or a support ticket. The customer just leaves, quietly, and you never learn they were there.

I want to talk about the page they landed on. Not the broken link itself, though we will get to where those come from. The page. The 404. Because the gap between a 404 that recovers that customer and one that loses them is about twenty minutes of setup, and most business sites never spend it.

A 404 is not the problem. The wrong 404 is.

Let me clear up the fear first, because it stops people acting. A 404 is simply the standard reply a web server gives when someone asks for a page that is not there. It is not a fault on your site. It is not a penalty. Google has said this plainly for years: the fact that some URLs on your site return 404 errors does not affect how your other pages rank or get indexed. Dead links are normal. Every site on the internet has them.

So a 404 will not damage your Google ranking. What costs you is quieter and more expensive: the customer who reaches one and leaves.

There is one genuinely harmful version, though, and it is worth naming. It is called a soft 404. That is when a missing page returns a "success" status to Google instead of a proper "not found" status, usually because the site was rigged to bounce every dead link to the homepage or to a near-empty page. Google discourages this directly. Soft 404s confuse search engines, waste the time Google spends crawling your site on pages that are not really there, and can be dropped from search anyway. In plain terms: faking a working page is worse than admitting the page is gone. Return an honest 404 and put something useful on it. You are allowed to serve whatever content you like behind that 404 status.

Where the dead links come from

You cannot stop 404s. You can only decide what happens when one is hit. It helps to know where they come from, because most are self-inflicted and predictable:

You deleted or renamed a page. The winter tidy-up. The old "Christmas hours" page. A product you stopped selling. Each one leaves a URL that people and Google have already bookmarked or indexed.
Someone typed the address wrong, or a link on another site points at you with a typo you cannot control.
You printed the URL somewhere permanent. A flyer, a van, a business card, a QR code. A web page can change in seconds. The flyer in someone's kitchen drawer cannot.
You moved the site and the new addresses do not match the old ones. This is the big one, and a botched move can strand every page you ever ranked for. If you are switching hosts or rebuilding, the missing redirects, not the migration itself, are what wreck your rankings.

That last category is a redirect job, not a 404 job, and I will come back to the difference, because people confuse the two constantly.

What a good 404 page actually does

The standard to aim for has nothing to do with clever design. The Nielsen Norman Group, who have researched web usability for decades, set out what any error page owes the person reading it. Their rules are blunt. Use plain language a non-technical person understands. Do not blame the visitor. Say briefly, and without drama, that the page could not be found. Then, and this is the part that matters, give them a way out.

A way out means real options, not a shrug:

A short, human line that says the page is gone and it is not their fault.
Your main navigation, so they can reach your shop, services or contact page in one click.
A search box, so they can look for what they came for.
A few links to your most popular or most important pages.
Your phone number or a contact link, because some people just want to talk to you.

Think about what that does for the garden centre. The customer scans the flyer, the offer page is gone, but instead of a dead grey screen they see the shop's menu, a search box and a line that reads "That page has moved on, but everything we grow is right here." That is the difference between a lost sale and a customer who finds the thing anyway. The same three-second window that decides whether someone stays on your homepage applies here too, on the page they never meant to visit.

One thing to resist: do not get cute. A 404 page is not the place for a long joke or an animation that takes a moment to load. The visitor is already slightly annoyed. Get them moving again, fast.

A good 404 page does one job: it turns a dead end back into a set of directions.

Building one that works, and testing it before you trust it

This is where the platform underneath your site quietly decides how much control you have. On full WordPress, the 404 page is just another template in your theme, called 404.php in classic themes or a 404 block template in newer ones. Every proper theme ships with one. WordPress serves it automatically whenever a page is not found, and you can edit every word and link on it.

You are not asking anyone's permission. You own the template.

That freedom is not universal. On some closed website builders you get whatever generic "page not found" screen the platform decided to hand you, in the platform's styling and, sometimes, with the platform's branding. If a stock error screen is genuinely all you will ever need, and you have no printed URLs and no plans to grow, that default is fine and one less thing to think about. For a very small, very static site, that is a fair trade. But the moment you want the 404 to carry your navigation, your search and your own tone of voice, you want the full template access that comes with a real WordPress install. That kind of control from day one is exactly what Web60's all-inclusive WordPress hosting is built around, so the page a lost customer lands on is yours to shape, not the platform's.

Whatever you build, verify it before you rely on it. Type a deliberately wrong address on your own site, on a staging environment first, and watch what loads. Does your navigation appear? Does the search box work? Does it return a true 404 status and not a soft 404 pretending all is well? A quick look in a browser answers the first two. Google Search Console answers the third, and it will list the URLs on your site throwing 404s and soft 404s, so you can see the real ones your visitors are hitting. Deploy the fixed template to production only once it behaves on staging.

The limit worth knowing

The honest catch is the mistake I see most often. A brilliant 404 page does not fix a page that simply moved. If you renamed your "services" page, or migrated the whole site, the right answer is a redirect that sends the old address straight to the new page, so the visitor never meets an error at all. The 404 is your safety net for pages that are genuinely gone, not a stand-in for redirects on pages that just changed address. Reach for a 301 redirect when the content still exists somewhere. Reach for the 404 page when it does not.

We learned that one the slow way, early on. We let a batch of moved pages 404 instead of redirecting them, reasoning that the tidy new 404 page would catch everyone. It caught them, and a fair number still left, because they had come for a specific page and been handed a menu instead of the thing they wanted. The redirects went in the next morning. Would not make that call again.

A moved page wants a redirect. A deleted page wants a helpful 404. Know which problem you have.

The upshot

A 404 page is the cheapest insurance on your website. It costs nothing, it takes an afternoon at most, and it earns its keep on the worst day: the one where an old link, a reprinted flyer or a deleted page sends a real customer to what should be a dead end. Get the honest status code right so Google is not misled. Put your navigation, a search box and a friendly line on the page so the visitor is not stranded. Keep an eye on which links are actually breaking, so you fix the ones that matter.

The broken link will happen. It happens to everyone. What the customer sees next is the only part you control, so make it the part that brings them back in.