A sitemap is a file, most often in XML format, that lists the URLs of a website and provides metadata about each page to crawlers. Without this file, search engines crawl the site by following internal links, which can leave orphaned or poorly linked pages outside the indexing scope. The sitemap acts as a structured inventory, transmitted directly to crawlers to complement their natural exploration.
XML Sitemap Tags: Those That Google Really Uses
Most guides focus on creating the file. Before getting there, understanding what Google reads (and ignores) in a sitemap helps avoid wasting time on ineffective parameters.
An XML sitemap contains several optional tags for each URL. Among them, only the lastmod tag holds real interest for Google. The engine can use it to prioritize the recrawl of a page, provided that the date corresponds to a significant change in content, structured data, or links. An artificially updated date (copyright change, automatic file regeneration) reduces the reliability of the signal and prompts Google to ignore it.
The changefreq and priority tags are ignored by Google. They still appear in the protocol specification, but optimizing them has no measurable effect on indexing or ranking. Focusing on these fields diverts attention from what matters: the accuracy of the listed URLs, the absence of error pages, and the reliability of lastmod.
To observe the concrete structure of a sitemap file, the sitemap of Horizon Net illustrates a standard XML format with its URLs organized hierarchically.
Sitemap and Crawl Budget: Why Page Visibility Depends on It
Search engines allocate a crawl budget to each site, which is the volume of pages that the crawler will explore during each visit. On a site with a few dozen pages, this budget is more than sufficient. On an e-commerce site, a multilingual portal, or a news site with thousands of URLs, the crawler only traverses a fraction of the site during each visit.
The sitemap directs the crawl towards the pages that deserve to be indexed. By explicitly listing priority URLs and excluding low-value pages (search filters, deep pagination pages, empty archives), the file helps the crawler dedicate its budget to strategic content.
Without a sitemap, the crawler follows internal links and may take several weeks to discover a recently added page that is poorly linked to the rest of the hierarchy. With an up-to-date sitemap and a reliable lastmod tag, the discovery of new content or substantial changes accelerates significantly.
Orphan Pages and Insufficient Linking
An orphan page is a URL that is not linked by any internal link. In theory, the crawler cannot find it on its own. The sitemap then becomes the only channel through which this page enters the indexing scope. This situation frequently occurs on sites that generate landing pages for campaigns or on online stores where certain product listings are only accessible via internal search.
Submitting a Sitemap in 2025: Methods That Work and the Obsolescence of Ping
Submitting the sitemap to search engines has evolved. A method that was once common, Google ping (an HTTP request sent to a notification endpoint), no longer works since 2023. Requests to this old endpoint may return a 404 error and do not trigger any useful processing.
The three currently operational methods are as follows:
- Direct submission via Google Search Console, in the “Sitemaps” section, where the URL of the file is declared and its processing status visible within a few days.
- Declaration in the robots.txt file, by adding a line of type “Sitemap:” followed by the absolute URL of the file. This method works for all engines that respect the convention.
- The Search Console API, useful for sites managed programmatically or for agencies that manage multiple properties.
IndexNow: A Complement for Frequently Updated Sites
For sites whose content changes very frequently, the sitemap alone does not guarantee quick discovery of each modification. Bing recommends complementing it with IndexNow, a protocol that transmits modified URLs to participating engines without waiting for the next visit from the crawler. The sitemap remains the basic coverage, while IndexNow accelerates the acknowledgment of sporadic changes.
Common Errors in an XML Sitemap That Block Indexing
A poorly configured sitemap can have the opposite effect of what is intended. Three errors frequently arise during technical audits.
- Listing URLs that return a 404 or 301 HTTP code. The crawler explores these pages, detects the error, and wastes crawl budget on unnecessary resources. Each URL in the sitemap must return a 200 code.
- Including non-canonical URLs. If a page has a canonical tag pointing to another URL, only the canonical URL should appear in the sitemap. Listing both creates a contradiction that the engine must resolve, often to the detriment of the desired page.
- Generating a static sitemap that is never updated. A file created at the launch of the site and then forgotten no longer reflects the reality of the hierarchy after a few months. A sitemap must be regenerated with each structural change to the site.
Most CMSs and SEO plugins offer automatic sitemap generation. Regularly checking in the Search Console that the file does not contain coverage errors remains a maintenance step not to be neglected.
The sitemap does not directly change a page’s ranking in the results. Its role is upstream: to ensure that the pages exist in the eyes of the search engine. An unindexed page does not rank for any query, regardless of the quality of its content or on-page optimization.
Maintaining a clean XML sitemap, with valid URLs and reliable lastmod dates, remains one of the simplest technical prerequisites to implement to protect a site’s visibility in the long term.
