Creating a custom 404 error page can be relatively simple or more complicated, depending on what technologies were used to build your website (your web server, framework used, etc). Learn more about the basics of creating a custom 404 error page.
On your custom error page, you should provide relevant information to keep the user's attention so they remain on your website. Some steps to achieve this goal include:
You can also use your custom 404 error page to track the source of broken links in your site.