Redirect Mapping Tool

What is a redirect mapping tool and when do you need one?

A redirect mapping tool matches broken or old URLs to the closest live page on your site. After a migration, a redesign or a new URL structure, hundreds of old URLs start returning 404. Finding a target for each one by hand takes hours. This tool cuts that to seconds, because it compares every old URL with every page in your sitemap.

For each row you get three candidates, a confidence score and a warning where needed. Then you export your choices as .htaccess, nginx, CSV or JSON. The matching runs in your browser, so your list of broken URLs never reaches our server. Our server only reads the sitemap you name.

Think of the result as a fast first draft, not a final decision. High scores are usually right, but you should always review the medium and low rows. At Talha Aslan and the team, we use this list as the first draft in our SEO consulting projects and make the final call after looking at the actual pages.

Where do you find the list of broken URLs?

A good redirect plan starts with a complete list of old URLs. The most reliable source is a full URL inventory from before the migration. If you do not have one, combine several sources:

• Search Console: the Not found (404) rows in the Page indexing report, plus old URLs that still earn clicks in the Performance report.
• Crawler: an archived sitemap of the old site or an export of a crawl you ran before launch.
• Server logs: URLs that return 404 but still get visits or bot traffic.
• Backlink reports: old pages that other sites link to.

You can upload these files straight into the tool. It finds the URL column in a CSV or a tab separated file from the header name or from the content. It also merges duplicates and skips invalid lines. To see the broken links on a single page, use our broken link checker as well.

How does the redirect mapping tool score URLs?

First, the tool splits every URL into meaningful words. For example, it strips the date folders from /blog/2019/05/what-is-seo and removes the number and extension from /product/12345-red-sneaker.html. As a result, it compares only the words that describe the topic.

Then it combines three measures. TF-IDF similarity comes first: words that are rare on your site weigh more than words that appear on every page. Next, Jaccard overlap looks at the share of words two slugs have in common. Finally, Levenshtein distance catches spelling differences and abbreviations.

After that, structure adjustments apply. A target in the same folder gets a small bonus, while a different language prefix lowers the score. That way, a page under /de/ rarely lands on an English target. A target that also sits in your broken list gets a penalty, because a redirect to it builds a chain. A score of 75% or more means high confidence, and 50% to 74% means medium.

What should you do when the confidence is low?

A low score means your site has no clear page that covers the topic of the old URL. By default, the tool then suggests the nearest parent category, or the homepage if no category exists, and adds a soft 404 risk warning to the row.

The warning follows Google's own advice. In its site move guide, Google recommends that you avoid redirecting many old URLs to one irrelevant destination such as the homepage. Such redirects can count as soft 404s. In that case, visitors do not find what they wanted, and the old page's signals do not pass to the new one.

For a low confidence row, follow this order:

1. Check the three candidates in the dropdown; sometimes the second one is right.
2. If you know a fitting page, enter it with Enter another URL.
3. If no similar content exists, choose 410 or keep the 404.

For a bulk change, set On low confidence to Leave empty (404) above the button. Then weak matches never reach your rules, and you add only the rows you are sure about.

How do you choose between 301, 410 and 404?

The choice depends on whether the content has an equivalent on the new site. If the content moved, or a new page answers the same question, a permanent 301 redirect fits. Google's redirects documentation describes a permanent server side redirect as a strong signal that the target should be canonical.

If the content is gone for good and nothing similar exists, a 410 is the honest answer. In practice, Google handles 404 and 410 the same way; both let the URL drop out of the index over time. Still, a 410 records that you and your team made that decision on purpose.

On the other hand, keeping a 404 is not always a mistake. Writing redirects for URLs that never had traffic or links and whose topic no longer exists only bloats your rules file. In short, 301 is for valuable old pages; for the rest, 410 or 404 gives a cleaner result.

How do you add the .htaccess and nginx rules?

On Apache and LiteSpeed servers, you add the rules to the .htaccess file. The tool writes RedirectMatch instead of plain Redirect. According to Apache's mod_alias documentation, Redirect matches prefixes, so a rule for /product also catches /products/shoes. RedirectMatch, by contrast, uses ^ and $ to match only that URL and treats the trailing slash as optional.

RedirectMatch cannot catch old URLs with query parameters such as index.php?page=about. Therefore the tool writes a separate mod_rewrite block for those rows. Place the rules above your WordPress or CMS rules; otherwise the CMS answers the request first.

For nginx, the tool writes one map block and a single if line. The map block goes inside http { } and the if line inside the matching server { }. Then test the configuration with nginx -t and reload the server. Once the rules are live, check a few URLs with our redirect checker; you should see a single 301 hop to the right target.

Why do chain and loop warnings matter?

A chain means that one URL redirects to another redirect, which then redirects again. According to Google's HTTP status code documentation, Googlebot follows up to 10 redirect hops. Even so, every hop slows crawling and makes visitors wait.

The tool flags two cases. A chain warning tells you that the target you picked also appears in your broken list; in other words, that target either returns 404 or will redirect itself. In that case, pick the final destination directly. A loop warning shows that source and target are the same URL. The tool writes no rule for that row, because the browser would enter an endless redirect.

In addition, if a URL from your broken list shows up as live in your target list, the tool leaves the row without a redirect and warns you. This usually means that one of your lists is out of date. Above all in large migrations, use these three warnings as your last check before launch.

How do you build a redirect plan for a site migration?

Build the redirect plan before launch, not after it. First, export the full URL list of the old site together with traffic, link and conversion data. Next, prepare the sitemap of the new site and match both lists with this tool. Then verify the URLs with the most traffic and links by hand.

On launch day, add the rules and test sample URLs. Submit the new sitemap in Search Console. Also update your internal links; even when a redirect works, an internal link should point straight to the final URL. Our XML sitemap generator helps you prepare the new URL list.

In its migration guide, Google recommends keeping redirects for as long as possible, generally at least one year. For a step by step list, read our website migration SEO checklist. We also explain how to move content safely in our content migration strategy guide.