A recent study by Bing found that most websites have XML sitemaps, and the “lastmod” tag is the most important component of these sitemaps.
The “lastmod” tag indicates when the web page linked by your sitemap was last modified and is used by search engines to determine how often your site is crawled and which pages to index.
However, the research also revealed a significant number of “lastmod” values set in XML sitemaps. wrongthe most common problem is the same date for all sitemaps.
After consulting with webmasters, Microsoft discovered that the date was set to the sitemap generation date, not the content change date.
To address this issue, Bing has renewal A crawl scheduling stack to make better use of the information provided by the sitemap’s “lastmod” tag.
This makes crawling more efficient by reducing unnecessary crawls of unchanged content and prioritizing recently updated content.
Improvements have already started on a limited scale and will be fully rolled out by June.
Additionally, Microsoft updated sitemap.org to improve clarity by adding the line:
“Note that the date should be set to the date the linked page was last modified, not when the sitemap was generated.”
Correct use of Lastmod tags
To properly set the “lastmod” tag in your sitemap, on each page of your sitemap,
The date should be in W3C Datetime format, the most commonly used formats being YYYY-MM-DD or YYYY-MM-DDThh:mm:ssTZD.
The date should reflect the last time the page was modified and should be updated regularly to ensure search engines understand the relevance and frequency of updates.
Here’s an example code snippet:
<最終変更>2023-01-23
Google Advice: Use Lastmod Tags Only After Significant Changes
Google’s crawlers also make use of the “lastmod” tag, and both major search engines offer similar usage suggestions.
Google Search Advocate John Mueller recently discussed the lastmod tag in the January issue of Google’s Office Hours Q&A session.
Although not mentioned in Microsoft’s blog post, it’s worth noting that Google recommends only using the “lastmod” tag for major changes.
Changing the date of the lastmod tag after a small edit could be seen as an attempt to manipulate the search snippet.
In summary
Recent research and efforts by Microsoft to improve the use of the “lastmod” tag in sitemaps will make crawling of web pages more efficient and effective.
Publishers are encouraged to update their sitemaps and lastmod tags regularly to ensure that their pages are indexed correctly and easily accessible by search engines.
Featured Image: Mundissima/Shutterstock
sauce: Microsoft
