Subjective factors
1: the quality of the site content cannot keep up. Just like my website, because my website is an enterprise site, there are some limitations in the content of the article, and there is not enough content. So I can only enrich the site through repeated content or pseudo-original content. However, the search engine algorithm has long been able to distinguish between site duplication and low-quality content, which is the main reason why my site is not indexed and the number of records is reduced. Therefore, I believe that the main reason for the reduction of the site's indexing is the content quality of its own factors.
2: The server is unstable. Many articles have explained the problem of server selection. For websites, a good server is like a good body, and the body is the capital of revolution. If the server encounters problems in three days, let alone optimization. If the server is unstable, the most direct result is the decrease in the site ranking and indexing. A search engine spider crawls our site like a common visitor. If the spider cannot open our site, it should not be said that crawling is included. In addition, after several such cases, the spider will think that your site has been closed, instead of accessing your site.
3: Black Hat technology. The so-called body is not afraid of shadow. As long as our optimization personnel use formal optimization technologies, they are not afraid of the punishment of search engines. However, due to the trend of interests, many webmasters are still willing to take risks and use the Black Hat technology to optimize the site. In the short term, your website may be indexed in large quantities. However, the search engine will review you later and punish you by reducing the number of indexed items.
4: The website is upgraded. The website revision and upgrade are inevitable for every website. As a result, the decrease in indexing is inevitable. In this regard, we should reduce the frequency of modification to the site to minimize the impact of modification on the record.
Objective reasons
1: Update of search engine algorithms. For each search engine algorithm update, many webmasters will find that the indexing may increase or decrease. In this case, the author believes that the webmaster should be calm, and algorithm updates are inevitable. It is their business to search engines to think about it. As long as our site is well optimized, not afraid of changes in search engines.
2: The website is attacked or infected with Trojans. As our webmaster, the most depressing thing is that the website is attacked or infected with Trojans, and the author's site has been hacked. What's even more depressing is that when you encounter this problem, you can only view the file modification time through ftp to determine which file has been modified. After you modify the source file to the site, the search engine may think that your site is a new face, you may have to face the dilemma of re-being reviewed by the search engine, which may lead to a reduction in the indexing of the site. In addition, unstable websites or Trojans caused by attacks may result in a search engine's distrust of your sites. This will eventually affect the recording.