A soft 404 is a state in which the server returns a success response code even though the page contains no meaningful content. Typically this involves discontinued products with an unavailability message, empty category listings, search results with no matches, or non-existent addresses redirected to the homepage. The search engine notices the discrepancy and removes the page from the index anyway, but in the meantime it repeatedly wastes crawl budget on it, and a user who clicks through leaves disappointed. The solution depends on the case: a genuinely non-existent address should return an error code, moved content should be redirected to the corresponding page, and a temporarily unavailable product should remain accessible with information about its return and an offer of alternatives. Empty listings are better left inaccessible or filled with meaningful content.
See also: Index bloat, Redirect chains, Availability and Delivery Time.
