How to Completely Ruin (or Save) Your Website with Redirects

Have you ever redirected a page hoping to see a boost in rankings, but nothing happened? Or worse, traffic actually went down? 

When done right, 301 redirects have awesome power to
clean up messy architecture, solve outdated content problems and improve
user experience — all while preserving link equity and your ranking
power.

When done wrong, the results can be disastrous. 

In the past year, because Google cracked down hard on low quality links, the potential damage from 301 mistakes increased dramatically. There’s also evidence that Google has slightly changed how they handle non-relevant redirects, which makes proper implementation more important than ever.

From Dr. Pete’s post - An SEO’s Guide to HTTP Status Codes

Semantic relevance 101: anatomy of a “perfect” redirect

A
perfect 301 redirect works as a simple “change of address” for your
content. Ideally, this means everything about the page except the URL
stays the same including content, title tag, images, and layout.

When
done properly, we know from testing and statements from Google that a
301 redirect passes somewhere around 85% of its original link equity.

The
new page doesn’t have to be a perfect match for the 301 to pass equity,
but problems arise when webmasters use the 301 to redirect visitors to
non-relevant pages. The further away you get from semantically relevant
content, the less likely your redirect will pass maximum link juice.

For
example, if you have a page about “labrador,” then redirecting to a page
about “dogs” makes sense, but redirecting to a page about
“tacos” does not.

301 redirecting everything to the home page

Savvy
SEOs have known for a long time that redirecting a huge number of pages
to a home page isn’t the best policy, even when using a 301. Recent statements by Google representatives suggest that Google may go a step
further and treat bulk redirects to the home page of a website as 404s,
or soft 404s at best. 

This
means that instead of passing link equity through the 301, Google may
simply drop the old URLs from its index without passing any link equity
at all.

While
it’s difficult to prove exactly how search engines handle mass home page
redirects, it’s fair to say that any time you 301 a large number of
pages to a single questionably relevant URL, you shouldn’t expect those
redirects to significantly boost your SEO efforts.

Better alternative: When necessary, redirect relevant pages to closely related URLs. Category pages are better than a general homepage.

If
the page is no longer relevant, receives little traffic, and a better
page does not exist, it’s often perfectly okay to serve a 404 or 410
status code.

Danger: 301 redirects and bad backlinks

Before
Penguin, SEOs widely believed that bad links couldn’t hurt you, and
redirecting entire domains with bad links wasn’t likely to have much of
an effect.

Then Google dropped the hammer on low-quality links.

If the Penguin update and developments of the past year have taught us anything, it’s this:

When you redirect a domain, its bad backlinks go with it.

Webmasters
often roll up several older domains into a single website, not
realizing that bad backlinks may harbor poison that sickens the entire
effort. If you’ve been penalized or suffered from low-quality backlinks,
it’s often easier and more effective to simply stop the redirect than to try and clean up individual links.

Individual URLs with bad links

The
same concept works at the individual URL level. If you redirect
a single URL with bad backlinks attached to it, those bad links will then point to your new URL.

In this case, it’s often better to simply drop the page with a 404 or 410, and let those links drop from the index.

Infinite loops and long chains

If
you perform an SEO audit on a site, you’ll hopefully discover any
potentially harmful redirect loops or crawling errors caused by
overly-complex redirect patterns.

While
it’s generally believed that Google will follow many, many redirects,
each step has the potential to diminish link equity, dilute anchor text
relevance, and lead to crawling and indexing errors.

One or two steps is generally the most you want out of any redirect chain.

New changes for 302s

SEOs typically hate 302s, but recent evidence suggests search engines may now be changing how they handle them — at least a little. 

Google knows that webmasters make mistakes, and recent
tests by Geoff Kenyon showed that 302 redirects have potential to pass link equity. The theory is that 302s (meant to be temporary) are so
often implemented incorrectly, that Google treats them as “soft” 301s.

So, not only do search engines limit us when we try to get too clever, but
they also help to keep us from shooting ourselves in the foot.