Studio Editor: Creating a Custom 404 Page
Customize the error page that site visitors see when trying to access a broken link. Design it to match your client's branding and add helpful links to keep visitors engaged.

Before you begin:
You must upgrade your client's site to create a custom 404 error page.
To create a 404 page:
Click Pages

on the left side of the editor.
Click Add New Page at the bottom.
Click Add under Page.
Give the page a name you can recognize.
Change the page's URL slug to "error404":
Hover over the page and click the More Actions icon

.
Select SEO Basics.
Enter "error404" under URL slug.
Tip: The page URL should look like the following example: https://www.mystunningwebsite.com/error404
Design the page to your liking. Below are some ideas:
Add links, buttons or a menu to help visitors navigate to other parts of your site. This minimizes the chances of your visitors leaving after getting the 404 error message.
Add vector illustrations related to error 404 from the Media Manager. You can find tons of free designs in the Media from Wix tab.
If necessary, you can hide the global header and footer on this page.
Tip:
Make sure to check how the page looks like on all breakpoints.