Share of linked URLs dead per site, by previous platform
| Previous platform | Sites | Median site dead share | Sites over 25% dead | Sites over 50% dead |
|---|---|---|---|---|
| Salesforce Commerce Cloud | 89 | 37.0% | 60.7% | 37.1% |
| PrestaShop | 80 | 29.9% | 52.5% | 28.8% |
| Magento | 88 | 23.9% | 48.9% | 18.2% |
| WooCommerce | 66 | 21.9% | 47.0% | 21.2% |
| WordPress | 83 | 21.7% | 44.6% | 19.3% |
| BigCommerce | 81 | 20.0% | 38.3% | 16.0% |
| Next.js | 85 | 20.0% | 47.1% | 22.4% |
| Other platforms | 87 | 15.4% | 35.6% | 16.1% |
| All | 659 | 22.7% | 46.9% | 22.5% |
Source: PageSpeed Matters, Oct 2026. Dead means a final 404 or 410 after following redirects.
Summary
Backlinks point at specific URLs. When a site changes platform and those URLs change without a redirect, the links still exist, but they land on a dead page and stop passing value to the content they were meant for.
We checked how often that happens across 659 sites that changed platform. On the median site, 22.7% of the non-homepage URLs other sites link to now return a 404 or 410. 46.9% of the sites have more than a quarter of their linked URLs dead.
What we measured
We looked at sites in the HTTP Archive crawl of the top 1M sites that switched platform, and checked up to 30 distinct non-homepage URLs per site that still have live backlinks. Homepages were left out, since the question is what happens to deeper pages.
We requested each linked URL in October 2026, followed any redirects and recorded the final response. A URL counts as dead if it ends on a 404 or 410. We got a final status for 15,661 of the 19,334 linked URLs.
Per-site shares use the 659 sites with 5 or more checked linked URLs. Because we only checked URLs with live backlinks, the results describe the old URLs that matter most for link equity, not every page the old site ever had.
The median site has lost more than a fifth of its linked URLs
On the median site that changed platform, 22.7% of linked non-homepage URLs now return a 404 or 410. Each of those is a link another site chose to give, now pointing at nothing.
The spread is wide. 46.9% of the 659 sites have more than a quarter of their linked URLs dead, and 22.5% have more than half dead. At the other end, 16.1% kept every linked URL alive. A clean migration is possible, but most sites in our sample lost at least some of the URLs other sites link to.
22.7%
Share of linked non-homepage URLs that return a 404 or 410 on the median site that changed platform.
Recent moves look worst
The share of dead linked URLs rises the more recent the move. The median site that switched in 2026 has 27.3% of linked URLs dead (229 sites). Sites that switched in the second half of 2025 sit at 22.7% (239 sites), and earlier switchers at 17.9% (191 sites).
There are a few likely reasons. Teams often keep fixing redirects for months after launch as broken URLs show up in their reports, so older migrations have had more time to repair the damage. Some dead links may also have been removed or updated by the sites that gave them, which would drop them out of our sample. Either way, the first months after a launch are when the most link value is at risk.
Salesforce Commerce Cloud exits lose the most
Sites leaving Salesforce Commerce Cloud lose the most. The median site has 37.0% of its linked URLs dead across 89 sites, 60.7% of them have more than a quarter dead and 37.1% more than half. Sites leaving PrestaShop follow, with a median 29.9% dead.
Sites leaving BigCommerce or Next.js lose the least among the named platforms, a median 20.0% each (81 and 85 sites), though the mixed group of other platforms was lower still at 15.4%. Magento (23.9%), WooCommerce (21.9%) and WordPress (21.7%) sit close to the overall median.
The spread likely follows how different the old URL structure was from the new one. Platforms with long, parameter-heavy or locale-prefixed URLs need more redirect rules, and more rules means more chances to miss some.
Linked WordPress images often break
Files are easy to forget in a migration because they are not pages. On sites that left WordPress, 24 of 30 linked /wp-content/uploads/ files on 17 sites now return a 404. Other sites had linked to those images directly, and the new platform usually stores media at different paths.
This rests on just 17 sites, so treat it as a warning sign rather than a rate. The fix is cheap, though: either keep the old upload paths serving the files or redirect each one to its new location.
What this means for your site
- Build the redirect map from backlink data. Export every old URL with external links, not just your sitemap, and map each one to its closest equivalent on the new site.
- Include files, not only pages. Images, PDFs and other linked files need their own redirects or need to stay at their old paths.
- Do not send unmatched URLs to the homepage. Redirect them to the nearest relevant page, or let them return a 404 if nothing matches.
- Recheck after launch, then again a few months later. Run your list of linked URLs against the live site in the first week and again later in the year, and fix anything that ends on a 404.
- If you already migrated, start now. Every dead linked URL you redirect today starts passing its value to a real page again.
Sources
- PageSpeed Matters analysis of backlinked URLs on 659 sites that changed platform, October 2026
- Google Search Central, redirects and Google Search: https://developers.google.com/search/docs/crawling-indexing/301-redirects
Embed this research
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<p style="font:14px/1.5 system-ui,sans-serif">Source: <a href="https://www.pagespeedmatters.com/resources/data-studies/backlinks-lost-in-migration">Backlinks Lost in Migration: Median Site Loses 23% - PageSpeed Matters</a></p>
Frequently asked questions
How many backlinks do sites lose in a website migration?
On the median site that changed platform, 22.7% of the non-homepage URLs other sites link to now return a 404 or 410. 46.9% of the 659 sites have more than a quarter of their linked URLs dead, and 16.1% kept every one alive.
Do broken backlinks get fixed after a migration?
Older moves look better. The median site that switched before July 2025 has 17.9% of linked URLs dead, against 27.3% for sites that switched in 2026.
How do I find backlinks pointing to dead pages after a migration?
Export the URLs on your site that have external links from a backlink tool, request each one on the live site and list any that end on a 404 or 410. Redirect each to its closest matching page.
A redirect map built from your backlink data, and rechecked after launch, keeps the links you have earned pointing at real pages. Need help with this? See our SEO migration services.