XML Sitemaps enables web sites to submit a list of their web pages with greater ease. Earlier methods require pages to be submitted manually on forms of search engines. Now, it is possible to compile a list of these pages and submit it to search engines on a specific format — XML.
This is especially helpful to large sites with dynamic content. Imagine having an e-commerce site that contains thousands of individual product pages, with details that change from time to time. Having to run a single script that crawls the whole web site in a couple of minutes to generate a list of web pages saves a lot more time than clicking over the pages and compiling them into Microsoft Excel.
Since the Sitemap is a structured XML document, it needs to have a required set of parameters which will be read by search engines:
- Begin with an opening <urlset> tag and end with a closing </urlset> tag.
- Specify the namespace (protocol standard) within the <urlset> tag.
- Include a <url> entry for each URL, as a parent XML tag.
- Include a <loc> child entry for each <url> parent tag.
It also has a few optional fields.
- <lastmod> The date of last modification of the file. This date should be in W3C Datetime format. This format allows you to omit the time portion, if desired, and use YYYY-MM-DD.
- <changefreq> How frequently the page is likely to change. This value provides general information to search engines and may not correlate exactly to how often they crawl the page. Valid values are: always, hourly, daily, weekly, monthly, yearly, never. The values placed here are mere estimates and can be overridden by search engines during their frequency of visits of these pages.
- <priority> The priority of this URL relative to other URLs on your site. Valid values range from 0.0 to 1.0. This value does not affect how your pages are compared to pages on other sites�it only lets the search engines know which pages you deem most important for the crawlers.
A sample XML Sitemap looks like this:
<?xml version="1.0" encoding="UTF-8"?>
Here are the following XML Sitemaps generators:
Once you have created your sitemap.xml file, you can submit it to Google Webmaster Tools using your Google Account. Yahoo! also announced recently that it is supporting the format, in collaboration with Google and MSN.