What is better? A custom 404 page or a generic one?
In 2004, Barry wrote that a custom 404 page is a "must have" for usability purposes. That's so true. But what about search engines? A forum member asks, would a generic 404 page be construed as duplicate content?
Well, first of all, if you're using a generic 404, who cares if it's duplicate content? 404 pages are not "content" though. They are "Error not found" pages.
But in all seriousness, the issue is that the return code should be 404, and if it is, the page won't be indexed. And further, 404 pages are not "content." They are "Error not found" pages.
The thing to be aware of is custom error solutions that return a 302 redirect code to get to the custom content. That can be trouble.
So make sure your pages have a 404. And as far as generic versus custom 404 pages, go with custom. It makes the user experience a lot more enjoyable (even if they can't find what they're looking for!) :)
Forum discussion continues at WebmasterWorld.