Redirect Map
Definition
A redirect map is a table of source paths and destination paths, used to keep old addresses alive after the content behind them has moved. Each row is a pair: the path someone might still request, and where that request should end up. Most maps are kept as a plain file — a CSV, a JSON object, or a hosting platform's own redirects file with one rule per line — so they can be reviewed and kept alongside the site. A good map is explicit about status, because a permanent move and a temporary one are different instructions to a browser and to a crawler. Wildcard rules, such as sending everything under /old-docs/ to /docs/, keep the file short but hide mistakes, so most real maps mix a few patterns with a long tail of one-to-one rows. Without one, every moved page becomes a broken link the moment someone follows an old bookmark.
Why It Matters
The links people have already shared are the ones you cannot edit. A site migration without a redirect map throws away every bookmark, every emailed link and every inbound link pointing at the old structure, and inbound links are the part that took years to earn. Search rankings travel with a redirect; without one the new page starts from nothing while the old one drops out of the index. The effort is small and the damage is not — an afternoon listing 200 old paths against their replacements, against a permanent hole in your referral traffic.
How It Works
Start from an inventory of the addresses that actually exist: your sitemap before the change, the busiest URLs in your analytics, and anything appearing in inbound links. Pair each one with its replacement, and flag anything with no replacement so you can choose deliberately between a parent page and a clean 410. A permanent move uses a 301 redirect, which tells browsers and crawlers to update their records and is cached hard — which is also why an incorrect one is painful to undo. Temporary moves use 302 or 307 and are not cached the same way. Rules are evaluated in order on most platforms, so put specific paths above wildcards, then check the finished map for loops and for chains longer than a single hop.
Real-World Example
A consultancy reorganises a set of guides published at advice-hub.99helpers.site, moving everything from /2024-guides/ to /guides/. They build a 40-row map before the change, test that each old path reaches the new page in one hop, and publish both together. The LinkedIn posts, the PDF footers and the two industry directories still pointing at the old paths all keep working. The three obscure guides they forgot show up in the 404 log within a week and get added.
Common Mistakes
- ✕Redirecting everything to the home page — a visitor who wanted one specific guide has to start their search over, and search engines treat the result as a soft 404
- ✕Chaining redirects as the site changes again, so an old URL takes three hops before it lands — each hop costs time and some clients give up
- ✕Building the map from the new sitemap instead of the old one — you can only redirect addresses that used to exist, and the old list is the only place they are written down
Related Terms
Site Migration
Moving a site to a new host, a new domain, a new URL structure, or some combination of the three. The files are the easy part; the addresses are where the damage happens.
Broken Link
A link that points at a page or file which is no longer there, so the visitor gets an error instead of the thing they clicked for. Most of the time the server answers with a 404.
301 Redirect
A 301 redirect is a response telling the browser that a page has moved permanently and giving the new address. The old URL keeps working for anyone who follows the old link, but everything that matters now lives at the new one.
Canonical URL
A canonical URL is the one address you nominate as the real home of a piece of content when several addresses serve it. You declare it with a rel=canonical link in the page head, and search engines use it to decide which version to index.
URL Slug
The readable, hand-picked part of a web address that names one particular thing — the 'acme-pitch' in acme-pitch.99helpers.site. It is chosen, short and made only of lowercase letters, digits and hyphens.
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