What is a Soft 404?
"Crypto 404" can make your site look untrustworthy
Recently, Google Webmaster Tools added the term “Soft 404” to its list of items. Most people know that a 404 error means “page not found” but what is a Soft 404?
According to Google’s webmaster blog, a Soft 404 is a page that shows up as “200” or OK, but then redirects itself to a different page. http://googlewebmastercentral.blogspot.com/2010/06/crawl-errors-now-reports-soft-404s.html. Confused? You don’t have to be. For instance, if you set your server to show a specific page (like the homepage) when a 404 error came up, this might be a soft 404. This is actually very helpful for people who have come in from other sites or old links, but can be confusing for a search engine.
Solutions to Soft 404 Errors. Luckily, Webmaster Tools tells you where the soft 404s are. This means you can add these pages to your HTACCESS (or ISAPI) file as 301 redirects to the proper page, or the most appropriate one. If the soft 404’s are coming from bad links on your own site, you may not have to redirect at all, but just fix your links.
Repairs to soft 404 errors are crucial for good search engine optimization and link building because you want to present a tight, concise site to Google (and Bing, and Yahoo) that does not confuse search engine spiders. If you have a site that has a bunch of redirects (also known as “crypto 404s”) then you essentially are creating confusion and straying into “doorway page” territory. Repairing soft 404 redirect errors should not take too much time for the average site, and at the end of the day you should be channeling your pagerank better because your navigation is referring to actual pages, and your 301 redirects are passing actual link popularity to the right places.
Notes and Special Information
Special note: Google Webmaster Tools identifies Soft 404 errors, but other engines may be considering them as well, so for the best SEO experience, make sure to address them.