The underestimated part of migration is often not page development but old URL handling. Bookmarks, indexed results, social shares, external articles, and email links do not change automatically. If the plan only checks the new homepage, important entry points can disappear.
Inventory old URLs first
Use server logs, search tools, sitemaps, old admin exports, backlinks, and known sections. The goal is not to preserve every obsolete page, but to identify paths that still receive traffic, remain indexed, or support business tasks.
Redirects need rules
One-to-one pages should use 301 redirects. Merged sections should point to the closest topical page. Retired content can return a useful 404 or 410. Sending every old URL to the homepage weakens user experience and search understanding.
Multilingual sites need relationship signals
Language paths, canonical links, hreflang, or equivalent signals should not contradict each other. If search engines cannot understand the relationship, they may treat pages as duplicates or index the wrong language version.
| Object | Action | Signal |
|---|---|---|
| Old article | 301 to new article | Status and target correct |
| Old section | New section or topic page | Users still find content |
| Retired content | 404/410 with helpful page | Clear recovery route |
| Sitemap | Submit new sitemap | Only valid URLs listed |
Post-launch observation matters more than launch day
Watch 404 sources, old-link clicks, indexing, form conversion, and regional traffic for at least two to four weeks. Old URL handling is part of delivery, not a decorative SEO task.