Website migration SEO checklist: move your site without losing rankings

"Will a new website hurt our Google rankings?" It is the first question business owners ask when we talk about a redesign or a platform move. It is the right question.

The honest answer: a migration does not hurt your SEO. A careless migration does. Rankings are tied to addresses, content and signals that Google has learned over years. Break those, and you start from scratch. Keep them, and the move can even help.

Here is the website migration checklist we used when we moved our own website from WordPress to Astro: 232 old URLs checked, none lost. Copy it, print it, tick it off.

Why migrations go wrong

Most ranking drops after a new website come from a handful of causes:

• Old pages disappear without a redirect, so links and bookmarks lead to a "page not found".
• Titles and descriptions get lost, because they lived in an SEO plugin that was not migrated.
• Content gets "cleaned up" and the paragraphs that ranked are deleted.
• Images lose their alt text and their file names.
• The new site blocks crawlers by accident, for example a staging setting left on after launch.

None of these are technical mysteries. They are list problems. That is good news: list problems can be solved with discipline.

What are the steps in a website migration?

Four phases, thirteen steps: list, map, move, check. The SEO migration checklist below follows that order.

Phase 1: Before you move anything

1. List every URL. Crawl your current site and export every address: pages, posts, categories, tags, images, PDFs. On our own site, that was 232 URLs.

2. Record what each page carries. For every URL, note the SEO title, meta description, main heading and whether it gets search traffic. Search Console shows which pages earn clicks.

3. Mark your most valuable pages. The pages with the most clicks, links or conversions get extra attention throughout.

Team planning on a whiteboard with sticky notes

Phase 2: Map old to new

4. Give every old URL a destination. Each one either keeps exactly the same address or gets a 301 redirect, a permanent forward that tells Google where the page went and passes on its history.

5. Redirect to the closest match, not the homepage. Sending every old page to the homepage loses relevance. An old blog post about hotel photography should land on the new post about hotel photography.

6. Avoid redirect chains. Old to new in one step. Not old to older to new.

Phase 3: Move and rebuild

7. Move content, not just design. Copy the text that ranks. Improve it if you want, but do not throw away the paragraphs that answer the question.

8. Carry over titles and descriptions page by page. On our migration, the SEO titles and descriptions matched on every page.

9. Keep images and alt text. Our 119 posts and 56 pages moved with their images and alt text.

10. Put key facts in the HTML. If your new site loads important content with scripts, some crawlers will not see it. Vercel's research found that the major AI crawlers it tested do not run JavaScript. Static HTML, which Astro produces by default, avoids that problem.

Phase 4: Check, launch, watch

11. Test every old URL before launch. Run the full list against the new site. Every one should return the page or a single redirect.

12. Check that crawlers are allowed. robots.txt open, no "noindex" left over from staging, sitemap updated and submitted in Search Console.

13. Watch Search Console for 30 days. Look at crawl errors, "not found" pages and indexing. Fix anything new within days, not weeks.

The part people forget: AI crawlers

Here is an insight most migration guides do not cover yet. In Vercel's study, AI crawlers hit a high share of invalid URLs: more than a third of their requests ended in errors. Vercel's advice was simple: keep redirects in place, keep sitemaps up to date and use consistent URL patterns.

In other words, the same redirect map that protects your Google rankings also helps AI assistants find your content instead of a dead end. Keep your redirects permanently. Do not remove them a few months after launch to "clean up".

How long does a migration take?

From our own projects, a typical WordPress to Astro migration takes 3 to 6 weeks. Large or multilingual sites take 6 to 10 weeks. The time depends mostly on the amount of content and the number of custom features such as forms or bookings, not on the design. Our fees are competitive, and the scope follows the same drivers: how many URLs, languages and custom features you have. That is why we scope the work after seeing your URL list.

What to take away

• Migrations do not hurt SEO. Lost URLs, titles and content do.
• Start with a full URL list. Every old address needs a destination.
• Redirect to the closest match, in one step.
• Put key content in HTML so every crawler sees it.
• Watch Search Console for 30 days, and keep your redirects for good.

When I sit down with a client on this, we start with the checks above.

Planning a new website or a platform move? See our website migration SEO service, how we handle WordPress to Astro, or book a call and bring your URL list.