{"id":7062027,"date":"2026-09-20T11:23:11","date_gmt":"2026-09-20T11:23:11","guid":{"rendered":"https:\/\/som2nypost.com\/business\/internet-business\/google-says-sitemap-cache-busting-is-a-bad-idea\/"},"modified":"2026-09-20T11:23:11","modified_gmt":"2026-09-20T11:23:11","slug":"google-says-sitemap-cache-busting-is-a-bad-idea","status":"publish","type":"post","link":"https:\/\/som2nypost.com\/?p=7062027","title":{"rendered":"Google Says Sitemap Cache Busting Is a Bad Idea"},"content":{"rendered":"


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\"Cache<\/a><\/p>\n

Some SEO people found a \u201ctrick\u201d and tried it on sitemaps. A sitemap is a file that tells Google which pages are on your website. This trick was supposed to make Google visit the sitemap every single day.<\/p>\n

Someone asked Google\u2019s John Mueller about this trick on Bluesky. They said they saw it on a big website; the sitemap URL was getting a new number added to it every day, like a date stamp. The person doing this skipped a proper Google feature called lastmod (which means \u201clast modified date\u201d) and used this trick instead.<\/p>\n

Google\u2019s answer was short and clear: don\u2019t do this; it\u2019s a bad idea.<\/b><\/p>\n

What Is Cache Busting<\/h2>\n

Cache busting is a real and useful trick, but it\u2019s meant for CSS and JavaScript files (the files that control how a website looks and works), not sitemaps.<\/p>\n

Here\u2019s how it works: when you update your CSS or JavaScript file, browsers sometimes keep showing the old version because it\u2019s saved in the visitor\u2019s browser (this is called \u201ccache\u201d). To fix this, developers add a small number at the end of the file name, like style.css?v=2. This tells the browser, \u201cthis is a new file; download it fresh.\u201d It\u2019s a smart and normal thing to do, for these files.<\/p>\n

How People Used This Trick on Sitemaps<\/h2>\n

Someone took this same idea and used it on sitemap files too, which is where the problem starts.<\/p>\n

Instead of using lastmod (the correct way to tell Google \u201cthis page changed\u201d), they added a changing number at the end of the sitemap URL, every single day. The idea was simple: if the URL looks new every day, Google has to visit it again and again.<\/p>\n

Here is the real conversation that happened:<\/p>\n

\u201cHi John, I\u2019ve been trying to learn some more about sitemap.xmls. Heard about this thing called cachebusting by adding a ?v=unix timestamp to the end of a sitemap url in a sitemapindex. In the Dev blog I could only find a comment on accurate lastmod values, I guess it applies too right?\u201d \u2014 @seoharbour<\/p>\n

John Mueller did not say yes or no right away. He asked a question back first:<\/p>\n

\u201cWhy would you use cache-busting in a sitemap file? Perhaps I\u2019m misunderstanding what your goal is though, feel free to elaborate!\u201d<\/p>\n

The person explained that they saw this happening on a big website, where the sitemap URL changed every day to force Google to visit again.<\/p>\n

Why Google Said It\u2019s a Bad Idea<\/h2>\n

After hearing the full story, Mueller gave a clear answer:<\/p>\n

\u201cI think that\u2019s a bad idea because you\u2019re signalling that the canonical URL for a piece of content should be constantly changing. That\u2019s not good for search engines; it\u2019s not good for your tracking. Having clean, stable URLs is important.\u201d<\/p>\n

He also pointed to a well-known web rule that says: web addresses (URLs) should not change often.<\/p>\n

In simple words, here\u2019s what this means:<\/p>\n

The address of your sitemap should stay the same, always.<\/b> When you keep changing the sitemap\u2019s URL every day, you\u2019re telling Google \u201cthis file\u2019s address keeps changing.\u201d That\u2019s confusing for Google. It\u2019s also bad for you, because your own tracking tools and reports get messed up too, you can no longer see clearly how often your sitemap is really being visited, because the address is different every day.<\/p>\n

Google did not say this trick makes Google crawl your site more or less. Google only said it\u2019s a bad practice because it makes your website\u2019s address look unstable.<\/p>\n

What You Should Use Instead<\/h2>\n

Sitemaps already have a proper, correct way to tell Google \u201cthis page has changed\u201d; it\u2019s called the lastmod tag. This simply means \u201clast modified date.\u201d<\/p>\n