What Is a 301 Redirect? A Plain English Guide for Business Owners

A 301 redirect is an instruction that sends anyone visiting an old web address to a new one instead, automatically, and tells Google the move is permanent.

Think of it as a change of address card. The letter still reaches you, and the Post Office updates its records rather than assuming you’ve vanished.

This is the most boring thing I will ever write about and one of the most expensive to get wrong. If a business tells me their enquiries fell off a cliff after a new website launched, this is where I look first, and it’s the answer more often than anything else.

Why the number 301

Web servers answer every request with a numeric code. You’ve met one of them: 404, which means the page isn’t there.

301 means “moved permanently, go here instead, and update your records”.

There’s also a 302, which means “moved temporarily, go here for now, but keep the old address on file”. The difference matters, and I’ll come back to it.

What actually happens without one

Say you’ve had a page at yourbusiness.co.uk/services/bathrooms for four years. It ranks well. Three suppliers link to it. It’s in your customers’ bookmarks and in an old email you sent.

You get a new website built. The new bathroom page lives at yourbusiness.co.uk/bathroom-installation. Nobody sets up a redirect.

Four things happen at once.

Anyone with the old link hits a 404.

Customers, suppliers, people clicking the link in your email signature. They see an error page and most of them leave.

The ranking goes.

Google had built up four years of confidence in that address. The address now returns nothing, so the ranking attached to it goes with it. The new page starts from scratch.

The links stop counting.

Those three supplier links were pointing at a page that no longer exists. The credit they were passing you evaporates.

Google keeps sending people to the dead page for weeks.

It takes a while to work out the page is gone, and in the meantime your best-performing result is an error.

With a 301 in place, none of that happens. Visitors land on the right page, most of the ranking strength carries across, and the links keep working.

When you need them

Five situations, and the first two are the ones that catch people out.

A new website.

If any address changes, every old address needs pointing at its closest new equivalent. This is the big one, and “we’ll sort the redirects after launch” is how damage happens.

Moving to a new domain.

Rebranding, changing your trading name, moving from a .co.uk to a .com. Every page needs mapping across.

Deleting or merging pages.

If you had three thin service pages and combined them into one good one, the three old addresses should point at the new page.

Switching to HTTPS.

The secure version of your site is technically a different address, so the insecure version needs redirecting to it. Usually handled automatically these days, but worth checking.

Tidying up duplicates.

If your site answers on both yourbusiness.co.uk and www.yourbusiness.co.uk as separate addresses, pick one and redirect the other.

301 or 302?

Simple rule. If the old address is never coming back, use a 301. If you genuinely mean to restore it, use a 302.

In practice, almost everything a small business does is permanent, so almost everything should be a 301. A 302 used by mistake for a permanent move means Google hangs on to the old address and the new one never fully inherits what the old one earned.

The main legitimate use for a 302 is something like a seasonal page, where you point a general address at a Christmas page for six weeks and then put it back.

The mistakes worth knowing about

Redirecting everything to the homepage.

This is the lazy fix, and I see it constantly. Someone knows they’ve got a hundred dead addresses, so they send all of them to the homepage.

It stops the 404 errors, which is why it feels like a solution. But Google treats a redirect to something irrelevant much like a dead end, so you keep almost none of the value. And the visitor who clicked a link about bathroom fitting lands on your homepage and has to start again, which is worse for them than an honest error page.

Every old address should point at its nearest real equivalent. Only use the homepage when there genuinely isn’t one.

Chains.

Page A redirects to B, B redirects to C, C redirects to D. Each hop is slower and loses a little, and long chains sometimes just stop being followed. Point A straight at D.

Loops.

A sends to B and B sends back to A. The page becomes unreachable entirely. Rare, catastrophic, and easy to spot once you know to look.

Forgetting the links you don’t control.

Your redirects fix your own site. The links from suppliers, directories and the local paper point at the old addresses and will keep doing so forever. That’s exactly why the redirect has to stay in place permanently, not for six months.

Removing them later.

A redirect is not temporary scaffolding. Leave them up. There’s no benefit to tidying them away and a real cost if you do.

How to check your own site

If you’ve had a new website in the last couple of years, this is worth twenty minutes.

1. Find some old addresses. Search site:yourbusiness.co.uk in Google, or look in Google Search Console under the indexing report for pages reported as not found.
2. Paste a few of the old ones into your browser. Do you land on a sensible page, or an error, or the homepage?
3. In Search Console, look at the not-found count. A handful is normal. Dozens after a redesign means the mapping wasn’t done.
4. Check your own old marketing. Old emails, printed leaflets, your Google Business Profile, your social profiles. Do the addresses still work?

If you find problems, this is a job for whoever maintains your site, and it is usually hours rather than days.

If you’re about to get a new website

One thing to insist on, and put it in writing before anyone starts.

Ask for a redirect map: a list of every current address and the new address it will point to, written before launch and signed off by you. Any developer who does this properly will have one ready. Anyone who waves it off is planning to deal with it afterwards, which means dealing with it after the damage.

It’s the single most valuable question you can ask in a web design meeting, and almost nobody asks it.

What this is part of

Redirects, sitemaps, making sure Google can find and read your pages: this is the technical end of SEO, search engine optimisation. It’s unglamorous and invisible when it’s right.

It’s also the end where a single oversight undoes years of work in an afternoon. A beautiful new website that lost every redirect is a worse business asset than the dated one it replaced.

If your enquiries dropped after a website change and nobody has given you a satisfactory explanation, send me your business name and postcode and I’ll run you a free audit. I’ll check whether your old addresses still resolve and what you lost, and tell you what’s recoverable. Often quite a lot of it is.