A 404 error message indicated that a page was not found. This is the standard response that a website (web server actually) gives when a page is not found. It is possible that a visitor has entered an url incorrectly, but the visitor may also have clicked on a broken link .
Is a 404 page bad for SEO
Is a 404 response bad for SEO? Google doesn't mind 404 pages. Google has regularly indicated that it is normal for some pages to disappear over time. Make sure you no longer have any internal links to the deleted page. If you fail to remove the links to the broken pageshowever that is an indication of a poorly maintained page.
If external links still refer to your deleted page, it is smart to forward the old page to a new page through a 301 redirect.
Custom 404 page
When a visitor receives this error message, a visitor will often leave your site. It is possible to (partly) prevent this by creating your own custom 404 page . This is a normal html page in which you explain that the page was not found. You can offer alternatives to the missing page (maybe you we looking for ...) and use a search form so that visitors may still find what they are looking for.
The important difference between 404 and 410
404 (not found) is the response that a web server gives when a page is not found. When a page is deleted you should actually give a 410 (gone) response. Google will visit 404 pages with some regularity to see if they have returned. If the website gives a 410 response, Google knows that this page has been deleted manually and Google no longer needs to spend your crawl budget on crawling this page. The Google crawler now has more budget to crawl your other pages. This is especially important for large sites that need to use Googles crawl budget efficiently.
Detect 404 errors
There are 3 methods for detecting a 404 page. All of them have their advantages and disadvantages
Google search Console
The first is the Google Search Console tools. There you can find an overview of the crawl errors. The disadvantage is that the search console data might be out of date and not all internal links linking to the broken page are shown.
Analyse log filesThe second and fastest way to detect 404 errors requires a little more knowledge. Through the log files of your site you can immediately see which 404 errors have occurred today. Various free tools are available on the internet to help you analyze your log. The major disadvantage is that you will only detect errors that have occurred today.
MarketingTracer On-Page SEO
The MarketingTracer on-page SEO tool will crawl your entire site and report back all the broken links and the 404 pages. The only disadvantage is that we are not a free tool (we are however priced very competitively)
Above the fold
Black hat seo
Advanced Search operators
Ranking Signal correlation