Is there a way I could change the text on the 404 page (‘Oops…etc.’) without going into and editing files? For example, as a custom CSS in the customizer?

(My site, by the way is diarypal.co.uk. WordPress version 3.9.2.)

Thanks,

Thanks for writing in,

Unfortunately, You can’t change text content with only CSS, However, you can try using Javascript instead,

Just add this code below in your Customizer > Custom > Javascript and change the content accordingly,

(function($){ 
	//Change OOPS
	$('.error404 .h-landmark span').text('I am 404 Heading');
	
	//Change You blew up the Internet.
	$('.error404 .p-landmark-sub span').text('I am 404 Sub Heading');
	
	//Change Content Text
	$('.entry-404 .center-text').text('I am 404 Content');
})(jQuery)

Let me know how it works,

Cheers

(function($){
//Change OOPS
$(‘.error404 .h-landmark span’).text(‘I am 404 Heading’);

//Change You blew up the Internet.
$(‘.error404 .p-landmark-sub span’).text(‘Not Logged In?’);

//Change Content Text
$(‘.entry-404 .center-text’).text(‘We can’t get to the page you were looking for. It might be because you have not logged in.’);
})(jQuery)

– Link to your site
– WordPress Admin username / password
– FTP credentials

Don’t forget to select Set as private reply. This ensures your information is only visible to our staff.

https://wordpress.org/plugins/404-to-start/

These two links also review a number of plugins:
http://www.hongkiat.com/blog/wordpress-404-pages-essential-tips-and-tools/
http://www.wpvirtuoso.com/6-best-free-wordpress-404-plugins/

I hope this helps.

Thank you.