What is an XML sitemap?

An XML sitemap is a machine-readable file that lists the URLs on your website. Search engines read it to discover pages they might otherwise miss and to learn a little about each one — when it last changed and how it relates to the rest of the site. It is written in XML, a plain-text format that is strict enough for a crawler to parse without guessing.

Where the format came from

Google introduced the Sitemaps protocol in 2005 to cope with websites that were growing faster than crawlers could keep up. Within a year the major search engines agreed on a shared standard at sitemaps.org, so the same file works for Google, Bing and others. That shared protocol is what this tool produces.

What a sitemap looks like

At its simplest, a sitemap is a list of <url> entries wrapped in a single <urlset> element:

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>https://example.com/</loc>
    <lastmod>2026-06-21</lastmod>
    <changefreq>weekly</changefreq>
    <priority>1.0</priority>
  </url>
  <url>
    <loc>https://example.com/about</loc>
    <lastmod>2026-05-02</lastmod>
  </url>
</urlset>

The four tags, explained

• loc — the full, absolute URL of the page. This is the only required tag.
• lastmod — the date the page last changed, in YYYY-MM-DD form. Search engines use it as a hint to recrawl changed pages sooner.
• changefreq — roughly how often the page changes (daily, weekly, …). Treated as a weak signal at best.
• priority — a hint from 0.0 to 1.0 of a page's importance relative to your other pages. It does not affect ranking against other sites.

When a sitemap matters most

A small, well-linked site may be crawled fine without one. A sitemap earns its keep when your site is large, brand new with few inbound links, rich in media, or has pages that are hard to reach by following links — such as archived posts deep in a paginated list.