Redesigns love new paths. Users and crawlers love old ones.

Without a redirect map, you donate equity to 404s. Search migration practice is consistent with common sense: map old→new, use permanent redirects when the move is permanent, update internal links, and monitor coverage after launch.

Map with indigo path

Draw the path before you move the city.

Why redirects are a product requirement

Bookmarks, ads, partner links, and search results do not update when you redesign. Every public URL you have ever shipped is a promise. Breaking the promise without a redirect is how you pay for new brand work twice: once to build it, once to recover traffic.

The map columns

Old New Type Owner Notes
/old /new 301 eng

Ship the map in the same release as the new information architecture. Remove chains (A→B→C). Prefer one hop. Test with curl and a crawler, not only the browser address bar after a warm cache.

Redirect map diagram

Generating the first map

  1. Export old sitemap and top landing pages from analytics
  2. Export CMS path list
  3. Sort by traffic
  4. Map top URLs manually; bulk-pattern the long tail
  5. Sample-test before go-live

Tooling

  • Store the map in git (redirects.json or platform _redirects)
  • Generate edge config in CI
  • Diff the map on every release
  • Alert on 404 rate after deploy

Common mistakes

  • 302 for permanent moves (weak signal to crawlers)
  • Redirecting everything to / (loses intent)
  • Forgetting query strings and trailing slash variants
  • Updating CMS paths but not the CDN redirect layer
  • Deleting redirects after a week because “migration is done”

Sample test plan

  1. Export top 100 legacy URLs by traffic
  2. curl -I each; expect 301/308 to correct final URL
  3. Confirm single hop
  4. Confirm final returns 200 and correct canonical
  5. Spot-check internal links on new templates

Automate critical paths in CI when you can.

International migrations

Redirect locale to locale, not everything to default English. Wrong-locale landings look like soft errors to users and crawlers. Pair with your locale URL strategy.

Aftercare

  • Watch 404 spikes for weeks
  • Keep the map; more inbound links appear for months
  • Update sitemaps and canonicals in the same change set
  • Pair with technical SEO index hygiene checks

Closing

A redesign without a redirect map is a content eviction with better typography.

Planning a URL migration? Start a project inquiry with old and new sitemap exports.

Discovery questions we ask

  1. What breaks if this is wrong in production next week?
  2. Who is paged, and is that written down?
  3. What does “done” mean in a checklist a stranger can run?
  4. Which metric proves the practice is working a month later?

If those answers are vague, the write-up is not finished — and neither is the system.

How this fits the rest of the journal

Pair this note with post-launch ownership, performance budgets, and technical SEO where relevant. Most failures are cross-cutting: a migration without redirects, a flag without expiry, a form without rate limits.

Closing reminder

Write the operating rules while the team that built the feature still remembers why. That is cheaper than reverse-engineering six months later during an outage.