How do you tell AI search when a page has changed? Sitemap lastmod and IndexNow explained

Why this matters for AI search

AI answers are only as current as the index behind them. Bing's webmaster blog says freshness signals influence how quickly updates show up in Bing's results and AI-generated answers, and points to lastmod and IndexNow as the signals to send. If your price, policy or opening hours changed and the search engine still holds the old page, the answer it builds will be wrong, however good your new page is.

This isn't a ranking trick. It only shortens the time between "you changed the page" and "the search engine knows".

The two signals compared

Step 1: make lastmod honest

lastmod should be the date the page's content last meaningfully changed, not the date the sitemap was generated and not "today" for every URL. Google says it uses the value only if it is consistently and verifiably accurate, so a sitemap that stamps every page with the current date teaches the crawler to ignore the field.

What to check:

1. Open /sitemap.xml and look at a few URLs. Do the dates differ from page to page?
2. Edit a page, wait for your CMS to regenerate the sitemap, and see whether only that page's date moved.
3. Don't bump the date for cosmetic changes such as a footer tweak.
4. Use ISO 8601 with the time, for example 2026-11-09T09:04:00+00:00, as Bing recommends.
5. Skip <priority> and <changefreq>. Google and Bing both say they ignore them.

We checked our own sitemap on 9 November 2026: all 45 URLs carry a full date-and-time lastmod, and the values differ per page. That is what you want to see. If yours shows the same timestamp on every URL, your CMS or plugin is stamping the whole file at once.

Step 2: add IndexNow

Does your platform already do it?

Check first. IndexNow's FAQ lists WordPress, Shopify, Wix, GoDaddy, Duda, Joomla!, Drupal, PrestaShop and several others as having native support or plugins, and says Cloudflare offers a native integration. Webflow and Squarespace aren't on that list, so for those you'd use a plugin, an automation or the manual method below. Check your platform's documentation rather than assuming.

Setting it up by hand

1. Make a key. 8 to 128 characters: letters, numbers and hyphens. A UUID works.

2. Host the key file. Create a UTF-8 text file named {your-key}.txt containing only the key, and put it at the root of your site, for example https://www.example.com/{your-key}.txt. Open it in a browser to confirm it loads without a login or firewall block.

3. Submit one URL with a GET request. Replace the values and URL-encode the page address:

https://api.indexnow.org/indexnow?url=https%3A%2F%2Fwww.example.com%2Fpage1&key=your-key

4. Or submit a batch (up to 10,000 URLs) with a POST to https://api.indexnow.org/indexnow:

{
  "host": "www.example.com",
  "key": "your-key",
  "urlList": [
    "https://www.example.com/url1",
    "https://www.example.com/url2"
  ]
}

5. Read the response code. The common ones:

You only need to send your request to one endpoint, because participating engines share submissions.

Rules worth following

• Submit when something meaningful changed: content, price, availability, a deletion or a redirect. Don't submit cosmetic changes.
• Wait at least 5 minutes before resubmitting the same URL.
• Deleted and redirected URLs are fair game: submit them so engines can drop or update the old address.
• Don't dump your whole site through IndexNow every day. It's meant for recent changes; the sitemap is for the full inventory.

What neither signal does

• It doesn't make a search engine index the page. Quality, duplicate content, a noindex tag, a robots.txt block or crawl quota can all stop it.
• It doesn't make an AI assistant cite you.
• It doesn't help a crawler that's blocked. If your firewall or robots.txt turns a bot away, no signal fixes that, so start with crawler access.
• IndexNow isn't a route into Google. Keep your sitemap accurate and submitted in Search Console for Google.

Run it automatically

If you'd like to see how a site scores on the basics AI tools look for, the free Web2Agents AI check scores your homepage with results on screen in real time. The €19 AI-Ready Kit runs all 36 checks on up to 25 pages and ranks the fixes.