---
name: replatform-sku-redirect-mapping
description: Use when moving a catalogue to a new platform and the URL patterns for products, variants, categories and facets are all changing at once.
---

# Replatform SKU Redirect Mapping

Migration checklists assume you can crawl the old site and map what you find, which fails on a large catalogue because the crawl misses orphaned and out-of-stock products that still hold links and rankings. The second failure is assuming SKUs map one to one: replatforms change variant handling, merge or split categories, and usually drop facet paths entirely, so a share of old URLs has no destination and gets bulk-redirected to the home page. That share is where the traffic loss comes from, and it is resolvable before launch if the map is built from the catalogue export instead.

## Was Sie vorher brauchen

- A URL inventory assembled from four sources and deduplicated: the database, the old sitemaps, 12 months of Search Console pages, 12 months of analytics landing pages
- Referring domain counts per old URL, so the linked tail can be prioritised
- The new platform URL patterns for products, variants, categories and any indexable facets, confirmed on staging rather than from a spec
- The old-to-new SKU and category identifier mapping from the migration team

## Methode

1. Assemble the inventory from all four sources, not from a crawl. Search Console and analytics history is what surfaces URLs that still earn traffic but are no longer linked from anywhere.
2. Join the inventory to the identifier mapping and let pattern rules generate the bulk of the map. Rules are more reliable and more reviewable than a hand-built sheet of 40,000 rows.
3. Isolate the rows the rules could not match and rank them by referring domains and organic entrances. This tail is small in count and large in value, and it is the only part needing human decisions.
4. Resolve unmatched URLs to the nearest genuine equivalent and accept a 410 for those with nothing behind them. Sending them to the home page is read as a soft 404 and burns crawl for months.
5. Decide variant handling explicitly before generating anything. A site that had a URL per size moving to one product page is a many-to-one merge, and every old variant URL still needs its own rule.
6. Test the ruleset against the full inventory on staging, checking status code, final destination and hop count. Chains through a rule left over from a previous migration are common and each hop costs crawl.
7. Keep the old sitemaps live and submitted for a few weeks after launch so the redirects are discovered quickly, then replace them with the new ones.
8. Re-run the full inventory against production on launch day and again at day 7, tracking the unmatched and error counts rather than waiting for traffic data to reveal the gap.

## Was dabei herauskommt

A tested old-to-new redirect map covering the complete historic URL inventory, with every unmatched URL either individually resolved or deliberately retired.

## Wo es schiefgeht

- Building the map from a crawl of the live site, which omits out-of-stock and orphaned products that still hold links and rankings
- Bulk-redirecting unmatched URLs to the home page or a top category, which is treated as a soft 404 and dropped
- Launching with chains from an earlier migration still in the stack, so each legacy URL costs several fetches to resolve
- Removing the old sitemaps at launch, which slows discovery of the redirects exactly when discovery matters most

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Aus der QuQi-Skill-Bibliothek - https://www.quqi.io/de/skills/replatform-sku-redirect-mapping