Chapter 21 — Further Reading

Site migrations are one of the topics where Google's own documentation is genuinely the best source, because Google is the party doing the reprocessing you are trying to survive. Start with Search Central's migration guides — they are specific, current, and free — before any agency blog post promising a "zero-loss" migration. The items below are grouped by how much you can trust them, in the spirit of the chapter.

Tier 1 — Canonical (start here; free and authoritative)

• Google Search Central — "Site moves with URL changes." The definitive guide for domain changes, CMS moves, and restructures: how to plan the move, set up 301 redirects, update sitemaps, and use the Change of Address tool. This is the primary source for §21.3–§21.6. Read it before you plan any migration.
• Google Search Central — "Site moves without URL changes." The companion guide for the "invisible" migrations — HTTP-to-HTTPS and same-URL redesigns — where the risks (canonical host, mixed content, dropped elements) are easy to overlook. The source for the redesign and HTTPS material in §21.1 and §21.5.
• Google Search Central — redirects and "How Google handles redirects" documentation. The official account of 301 vs. 302, that permanent redirects pass ranking signals, that redirect chains should be avoided, and that irrelevant redirects are treated as soft 404s. The backbone of §21.3–§21.4.
• Google Search Central — the Change of Address tool documentation. What it does, when it applies (domain moves, not protocol-only or subdomain changes), and how to use it alongside the redirects.
• Google Search Central — "HTTPS as a ranking signal" (2014 announcement) and the HTTPS/TLS docs. The Tier-1 confirmation that HTTPS is a lightweight ranking signal, and the practical migration guidance. The source for the HTTPS material in §21.1 and Case Study reference points.
• Google Search Central — the Search Console documentation for the Pages (indexing) report, URL Inspection, sitemaps, and Crawl Stats. The tools you actually watch during a migration (§21.6). Read alongside Chapter 27.
• Google Search Central — guidance on soft 404s, noindex, and robots.txt. The concepts behind the chapter's two central cautions: the lazy-homepage soft 404 and the staging-noindex catastrophe. Pairs with Chapter 14.

Tier 2 — Reputable secondary (useful, but verify against Tier 1)

• Migration guides and checklists from established SEO tool vendors and agencies. The better ones (from the makers of the major crawlers and audit tools) are genuinely useful as operational checklists — step lists, spreadsheet templates, timing plans. Read them for the workflow, but confirm any claim about how Google treats a redirect or how much equity transfers against Google's own docs, and treat any "we recovered X% in Y weeks" figure as a single self-reported anecdote, not a law.
• Screaming Frog's documentation and migration/redirect-mapping guides. Because the free crawler is the standard tool for building and testing a redirect map, its own docs on crawling a staging site, list-mode crawling, and auditing redirect chains are practical and reliable for the how, if not the why.
• Documented post-mortems of real, public migrations (retailer replatforms, publisher domain moves, large HTTPS rollouts) in the trade and mainstream financial press. Valuable for the shape of what goes wrong — and for the honest reminder that attribution is messy — but the specific numbers are context-bound and often conflate SEO with UX and business factors. Read them as cautionary patterns, not precise data.

Tier 3 — Constructed teaching material (this book)

• Rivertown Home Services — the running project; the Chapter 21 theme-migration checklist (Figure 21.4) and the annotated inventory and redirect-map excerpts (Figures 21.1–21.2), all figures illustrative.
• "The Domain Move That Forgot the Map" — the labeled composite in Case Study 2, built from real, common industry patterns; every number is illustrative.
• The Marks & Spencer 2014 relaunch (Case Study 1) — a real, public event; the documented facts come from the company's own reporting and the contemporaneous press, and the SEO-specific reading is labeled as practitioner analysis, with no invented traffic figure.
• Figures 21.1–21.4 and the constructed report/map excerpts in the exercises — all labeled constructed teaching examples.

Suggested order

1. Read "Site moves with URL changes" first — it is the master checklist and it frames everything else.
2. Read "Site moves without URL changes" next, especially if your migration is an HTTPS move or a same-URL redesign (the ones people underestimate).
3. Skim the redirects documentation until "301 passes signals," "avoid chains," and "irrelevant redirect = soft 404" are reflexes.
4. When you are ready to build a map, open Screaming Frog's crawling/redirect docs and crawl your own site to produce the inventory from §21.2.
5. Save the real migration post-mortems for when you want to feel the stakes — read two, and notice how often the failure was a missing redirect, a shipped noindex, or a launch that changed three things at once.

A habit to carry forward: whenever you read a migration "guarantee," ask what does this promise about the dip, and what does it promise about recovery? Honest guidance promises a protected transfer and a fast recovery; it never promises that traffic will not move at all. The moment a source promises zero loss, you have learned something about the source.