Will a website redesign hurt your SEO, and how do you keep the risk low?

This guide comes from the website redesigns we run on a client's existing domain, with every URL redirected, and from Google's own site-move documentation. If people already find your site on Google and you are about to rebuild it, read this before work starts. Looking after rankings once the new site is live is what our monthly SEO service does.

Why does a new website lose its SEO?

Because the things Google ranked the old pages on were changed or lost during the rebuild. Google doesn't rank a website as a whole; it ranks pages, one at a time, on their address, title, headings, text and the links pointing at them. Lose any of those and the page loses part of what made it rank.

These are the seven causes we see most often.

• URLs changed with no redirect. Links from Google, from LINE chats customers shared and from other sites all land on a 404.
• Every old page redirected to the home page. It looks tidy, but Google can treat it as a page that does not exist (a soft 404), and the value of the old links goes with it.
• Titles and H1s rewritten until the ranking words are gone. A page once named after exactly what people search for becomes "Our Products".
• Text cut back so the design looks clean. The paragraphs that answered the searcher's question disappear, leaving pictures and buttons.
• The test site's noindex or robots.txt block goes live with it. On WordPress it is the "Discourage search engines from indexing this site" box, left ticked.
• Thai URLs switched to English with no redirects. Many Thai sites use Thai-script URLs, so switching them to English changes every URL on the site.
• Text that only appears after JavaScript runs. Some new builds need scripts before any text shows, so crawlers that don't run them, most AI crawlers included, see an empty page.

Design, platform or domain: how risky is each change?

A new design on the same URLs is the lowest risk, and a new domain is the highest, because every page moves address at once. The more you change in one go, the more can go wrong, and the harder it is to find the cause if rankings fall.

So our advice is simple: don't change a URL that doesn't need to change. The safest redirect is the one you never have to write. If the old site is slow or dated but still ranks, change the design and the speed first, and leave a new platform or domain for a later round.

A real example: CDV Thailand changed its home page without touching a URL

CDV Thailand is a cloth bag factory in Bangkok. Its WordPress site already ranked well for each product type, but the home page didn't show for the phrase factory customers actually type. We rebuilt the home page inside the existing site, kept every URL and every ranking heading line for line, and left the theme alone.

The work went live one batch a week. Before each batch we saved a copy of the old content, and nothing that touches the whole site, such as plugins or cache settings, went out in the same week as a content batch. If a number moved, we knew which batch moved it and could roll it back at once. What we measured: desktop layout shift (CLS) fell from 0.45 to 0, three unused plugins came out, and the product schema warnings in Search Console were cleared.

What should you save from the old site before the rebuild starts?

Save three things before anyone touches the site: a list of every URL, your Search Console numbers and a copy of the old content, all dated. That record is the only thing that can tell you, three months later, whether a drop came from the rebuild. Without it, everyone blames a Google update.

• Every URL, from the sitemap and a full crawl with a tool such as Screaming Frog, which is free up to 500 URLs, including PDFs and images that get visits.
• Your top pages and the searches behind them, from Search Console, for the last 3 months and the same months a year earlier, so a seasonal dip can't fool you later.
• Pages other sites link to, from Search Console's Links report. These need a redirect most of all, even when they get few visits.
• The title, description, H1 and text of every ranking page, saved to a file so the new site can be compared page by page.
• Enquiries and sales from Google in GA4, by landing page, because rankings matter for what they bring in.
• Schema, forms and tracking code such as GA4 and the Meta Pixel. All of it has to come across to the new site.

The other thing people forget is timing. Don't launch just before your busiest season, whether that is Songkran, the end of the year or the high season for tourism, because Google has to reprocess every changed URL and rankings can move while it does.

If the old site is already gone, the Wayback Machine may still have it

The Internet Archive's Wayback Machine keeps copies of public web pages, captured from time to time. Type web.archive.org/web/*/example.com/* into the address bar, with your own domain in place of example.com, and it lists every URL it has captured. That gives you the old URL list for the redirect map even when the old server is empty.

When we rebuilt the site for Volcano Pooltable, a pool table maker, the old sizes, prices and installation photos were already gone from the old site. From the archive's copies we recovered 128 full-resolution photos and 12 pages of content. The prices in those copies were years old, so the shop confirmed every figure before it went on the new site.

A tip if you are doing it yourself: add id_ after the date stamp in a Wayback URL and you get the original file without the Wayback toolbar. And if the old site was ever hacked, don't restore its old database or backup wholesale, because any injected spam pages come back with it. Take only the text, figures and photos you have checked.

How should 301 redirects be mapped, and how long should they stay?

Map each old URL to the new page that answers the same question, one to one, and keep the redirects for at least a year, as Google advises. This map is the most important file in a site move: get it complete before launch and most problems never happen.

1. Match by topic, not by how the URL looks. The old canvas bag page goes to the new canvas bag page, even if the new URL looks nothing like the old one.
2. Never send everything to the home page. Google says not to redirect many old URLs to one irrelevant destination, such as the new site's home page.
3. One hop to the destination. Don't let A go to B and B to C. If the old site already has redirects, point them straight at the final page. Where a chain truly can't be avoided, Google's ideal is no more than 3 hops.
4. Use a server-side 301. A 301 or 308 tells Google the page has moved for good and to show the new URL. A 302 is temporary, so Google keeps showing the old one, and a JavaScript redirect is a last resort.
5. Decide each page that has no match. If it gets visits or links, build a new page for it. If a category is the honest nearest match, send it there. If it gets nothing and holds nothing, let it return a 404 or 410 on purpose.
6. Point internal links straight at the new URLs. Menus, footers and links in the text shouldn't run through a redirect, and canonical tags must point at the new URLs, not the old ones.
7. Keep the redirects for at least a year, and longer while anything still links to the old addresses. There is no safe date to delete them while people still click the old links.

• 1 yearthe minimum Google advises keeping redirects for
• 3 hopsGoogle's ideal ceiling when a chain can't be avoided
• 180 dayshow long Change of Address forwards signals to a new domain
• 6 weeksof weekly Search Console checks we run after a relaunch

Why did CDV ship weekly batches when Google says to move every URL at once?

The two don't conflict. Google recommends that small and medium sites move all their URLs at once rather than one section at a time, and that advice is about changing URLs. CDV changed no URLs at all; what changed was content and design on the same URLs, and shipping that in batches let us measure and roll back one change at a time. In short: if URLs must move, move them in one go; if content changes on the same URLs, change it in batches.

What should you check on launch day?

Open the 20 old URLs that used to get the most clicks before anything else: each should land on the right new page in one hop. Then check robots.txt, noindex and canonicals, and submit the new sitemap. Most of it takes minutes, and skipping it is how a site goes missing from Google for days without anyone noticing.

• Remove the test site's block. On WordPress, untick "Discourage search engines from indexing this site" under Settings > Reading, and check that no important page still carries a noindex.
• Test the top 20 redirects one by one, including URLs with a ?, a trailing / or capital letters. Go slowly: fire hundreds of requests at once and the server rate-limits you, which looks exactly like a broken redirect.
• Read robots.txt line by line. There must be no Disallow: / left over from the test site, and never block the old URLs: Google has to crawl them to see the redirects.
• Old URLs must redirect, not still load. If both the old and new addresses open, you have two copies of the site competing with each other.
• Submit the new sitemap in Search Console and Bing Webmaster Tools, listing only live new pages that return a 200, never redirects.
• Make a real test enquiry. Tap the LINE button, send the contact form and watch it arrive in GA4's Realtime report.
• Update the links you control elsewhere. LINE OA, your Facebook page, Google Business Profile, ads and any Shopee or Lazada shop should point at the new URLs.

After launch, how long can rankings wobble before it is a problem?

A small or medium site usually wobbles for a few weeks. Google says to expect temporary fluctuation in rankings during a move, and that a medium-sized site takes a few weeks for most pages to move. A page whose impressions fall to zero overnight isn't wobbling, though. That is a technical fault to fix at once.

On our redesigns we check Search Console every week for six weeks after launch and fix any page that drops straight away. A problem found on day one costs a day; found in month three, it has cost a quarter.

Rankings already dropped after a new site: how do you fix it?

Compare the old URL list with Search Console's Not found (404) report, then put back what went missing, starting with the pages that used to get the most clicks. Some pages come back quickly and some may not come back at all, so the question isn't whether everything can be saved but which pages are worth saving first.

1. Rebuild the old URL list from the old sitemap, Search Console's page reports or the Wayback Machine, if nobody saved one.
2. Open each URL and note whether it returns a 404, lands on the home page or reaches the right page.
3. Sort by old clicks and fix the redirects for the pages that used to bring the most visitors first.
4. Put the ranking titles, H1s and paragraphs back if the new site dropped them, from your saved file or the archive's copies.
5. Ask Google to recrawl the fixed pages with Search Console's URL Inspection tool, then compare the numbers every week.

If you would like us to work through the whole site and fix it, see our monthly SEO service.

Renaming the business or moving to a new domain: what else is needed?

Everything above, plus four more things: file a Change of Address in Search Console, keep renewing the old domain for at least a year, keep its redirects running, and update the links in LINE OA, Facebook and Google Business Profile.

• Change of Address goes in after the 301s are live, with both domains verified in Search Console under the same account. It runs for 180 days, during which Google favours the new site for crawling and passes on the old one's signals.
• Renew the old domain. Google recommends paying for it for at least a year. Let it lapse and someone else can register it, and every redirect switches off with it.
• Change of Address isn't for a move from HTTP to HTTPS, a switch between www and non-www, or URL changes inside the same domain. Redirects and a new sitemap cover those.
• Thai-script domains work the same way, like Volcano's โต๊ะพูล.com. In server settings the name appears in its Latin form, starting with xn--.

Hiring someone for a redesign: what should you get in writing?

Ask for these five things in writing before work starts. A builder who answers all five clearly has moved sites before.

• The full map of old URLs to new ones, as a file you keep.
• Redirect test results for every old URL, before and after launch.
• The Search Console baseline and a before-and-after comparison.
• How many weeks they will watch the site and fix dropping pages after launch.
• A rollback plan if something breaks on launch day.

If you are comparing several builders, read how to choose a web design company and what to check before you hire next.