@ Header ("http/1.1 404 not found ");
@ Header ("status: 404 not found ");
Echo 'echo 404 ';
Check whether 404 is set successfully. You can use the firebug plug-in of firefox to check whether is set successfully.
When firebug has been installed, open the 404 status code page in the firefox browser and click the bug icon in the lower right corner to start the "network" tag, open "network-all/html-headers" in sequence. If everything is normal, you can see the page parameters including headers and responses.
404 page impact on the website
It has little impact on seo tutorials. But yes, it is always better than no. If you have this permission, you 'd better set the 404 page. This is the same as a website map. Not all websites have to be set, but sometimes it is necessary to set it.
If you want to set a 404 page, you should consider the user experience rather than seo.
Let's take a look at the definition of apache 404.
In apache, setting the 404 error page to set the 404 error page for apache server is simple. You only need to add the following content to the. htaccess file: errordocument 404/notfound. php