[SEO ranking drop] Types and causes of crawl errors

April 20, 2015 May 12, 2022 Technical SEO , crawl countermeasures , SEO measures , internal measures

What is crawl error?

I think that some people may not hear much about crawl errors, so I will explain first.
A page where GoogleBot, a Google crawler, could not crawl, that is, a page that could not be confirmed.
Have you ever seen such a page with a search engine?

This is the crawl error state. I often see 404!
There are other types, but I will explain later.

Just because of this crawl error does not drop sharply, but Google is "malicious" even if you do not intend to make a large amount of crawl errors. If you think, it may affect the ranking.

Type of crawl error

There are two main types of crawl errors.

・ Site error… The crawler cannot access the site at all
・ URL error… In the program bug,

is a page that is not in a state where there is a page, but a state page that does not transmit it. State cannot be found

A message appears in the webmaster tool, so you can check the cause by clicking the URL with an error.

Main cause

There is a status code to display the cause.
There are quite a few types, but I will pick up common code and introduce them.

・ 404… There is no requested page
・ 403… access prohibition
・ 503… Temporary access is not possible
・ 400… illegal request
・ 408… Timeout

Looking at this, I feel like I did something wrong, but it was a warning that "I'm an error, but is it okay?
" Do not erase it in the dark because there is a law.

How to eliminate crawl errors

There are various ways to deal with errors depending on the cause, but this time we will introduce how to eliminate common 404 errors.
The 404 error does not have a page for some reason from the previous explanation.
The first thing I doubt at this time is, "Are you changing the URL of the site?"

For example, suppose a blog post is uploaded once in "20150420Brog.html" and is indexed to a crawler. However, after this, when I thought "Oh, I made a mistake in the spell" and I changed the name to "20150420Blog.html" and uploaded it up, when I accessed "20150420Brog.html" from the search engine, this page is a 404 error. It will be displayed.
There is a page, but the name has changed, so it will be treated as a page that will not be a page ... In such a case, I will redirect well and inform Google that it has changed from "0150420Blog.html" to "20150420Blog.html". Sho.

Technical SEO , crawl countermeasures , SEO measures , internal measures

Posted by LSD_ADMIN