By Mehdi HassanWhat should you benchmark before migrating a website?
Before migrating a website, benchmark search performance, analytics, the full URL inventory, backlinks, page speed and the technical setup. Together these answer the only question that matters after launch: did anything break, and if so, where?
The benchmark is step one of our website migration SEO checklist, and it's the step most often skipped. Without it, a post-launch dip turns into an argument instead of a diagnosis. With it, you can point to the exact pages and queries that changed.
Source | What to export | Why you need it |
|---|---|---|
Search Console | Clicks, impressions, position by page and query | The baseline for rankings and traffic |
GA4 | Landing pages, sessions, conversions | Proves which pages drive leads, not just visits |
Crawler | Every URL with status, title, meta, canonical, H1, word count | The source for your redirect map |
Backlink tool | Top linked pages and referring domains | Tells you which URLs must never 404 |
Core Web Vitals | Field data and lab scores for key templates | Shows whether the new site got slower |
Old platform | Redirect rules, robots.txt, sitemaps | These disappear with the old host |
Page snapshots | Raw HTML of top pages | Proof of content, schema and metadata |
How do you export Search Console data before a migration?
Export Search Console performance data by page and by query for the longest range available, plus the pages report showing what's indexed. Search Console keeps a limited history, so if the old property ever goes away or the domain changes, data you didn't export may be hard to recover.
Export pages
In the Performance report, set the longest date range, open the Pages tab and export clicks, impressions, CTR and position.
Export queries
Do the same on the Queries tab. Then export queries for each of your top pages individually, since that's what you'll compare later.
Get past the row cap
The interface export is capped. For larger sites, pull data through the Search Console API or a reporting connector so you capture the long tail.
Save the indexing report
Export the Pages indexing report, including excluded URLs and their reasons. It shows what Google already ignores.
Record the sitemaps
Note which sitemaps are submitted and how many URLs each reports as indexed.
How do you crawl a site before migration?
Crawl the site before migration with a desktop or cloud crawler set to follow every internal link, read the sitemap and include non-HTML files. The crawl gives you the complete URL inventory that your redirect map is built from.
- Include everything: HTML pages, PDFs, images, paginated archives, tag and category pages and anything in the sitemap.
- Capture metadata: status code, title, meta description, canonical, meta robots, H1, word count, hreflang and structured data.
- Capture links: inlinks per URL, so you can spot important pages the new navigation might orphan.
- Combine sources: add URLs from Search Console, analytics and backlink exports that the crawl didn't find. Orphan pages still rank.
- Save the file with the date, and don't overwrite it.
This combined list becomes column A of your 301 redirect map template. If you're moving off WordPress, our guide on exporting WordPress content covers the content export that runs alongside the crawl.
What analytics and conversion data should you save?
Save GA4 landing page data with sessions, engaged sessions and key events for the same period as your Search Console export. Rankings tell you about visibility, but conversions tell you which pages pay for the site.
Export organic landing pages separately from all traffic, and note which forms and events fire on each template. Migrations often break form tracking without breaking the forms themselves. Record your current analytics tag setup, consent configuration and any cross-domain settings so the new site can match them.
Which backlink and Core Web Vitals data matters?
From backlink tools, save the list of your most-linked pages and the referring domains behind them. From Core Web Vitals, save field data for each key template and lab scores for the homepage, a product page and a blog post.
Backlinked URLs are the ones that can never return a 404 after launch, so flag them in your redirect map. For speed, field data from real users is what Google uses, so record it per template. Then compare the same templates on the new platform once you've moved.
The technical files people forget to save
Three things vanish when the old platform is switched off. First, the existing redirect rules: old sites often carry years of redirects from earlier renames, and losing them breaks links that were already being forwarded. Export them and add them to the new map, pointing straight at the final URL.
Second, robots.txt and every sitemap file. Third, raw HTML snapshots of your top pages, saved as files, not screenshots. They record titles, schema, FAQs and copy exactly as crawlers saw them, which is the evidence you'll need if a page loses rankings and someone asks what changed.
How do you use a pre-migration SEO benchmark after launch?
Use the benchmark after launch by comparing the same pages and queries week by week against the same weeks before. Look at page level, not site totals, because a site-wide number can hide one template that broke.
Re-crawl the old URL list on launch day and check every row resolves to a 200 in one hop. Compare titles and word counts on top pages against your snapshots, and check that the forms you recorded still fire. If clicks fall, our guide to traffic drops after a website migration gives the diagnosis order, and our website QA testing guide covers the launch-day checks in detail.
