URL Structure Change - 301 Redirect - on large website

[Myntra]

Hi Guys,

I have a website which has approximately 15 million pages indexed. We are planning to change url structure of 99.99% of pages but it would remain on same domain.

eg: older url: xyz.com/nike-shoes; new url: xyx.com/shopping/nike-shoes

A benefit that we would get is adding a related and important keyword in url. We also achieve other technical benefits in identifying the page type before hand and can reduce time taken to serve the pages (as per our tech team).

For older URLs, we are planning to do a 301 redirect. While this seems to be the correct thing to do as per Google, we do see that there is a very large number of cases where people have suffered significantly on doing something like this :

Here are our questions:

1. Will all page rank value will be passed to new url? (i.e. will there be a 100% passing of PR/link juice to the new URLs)

• Can it lower my rank for keywords? (currently we have pretty good rankings (1-5) on many keywords)

1. If there is an impact on rankings - will it be only on specific keywords or will we see a sitewide impact?
2. Assuming that we have taken a hit on traffic, How much time would it take to get the traffic back to normal? and if traffic goes down, by what percentage it may go down and for how much time. (best case, average case and worst case scenarios)

• Is there anything I should keep in mind while doing this?

I understand that there are no clear answers that can be given to these questions but we would like to evaluate a worst case/best case situation.

Just to give context : Even a 10 day downtime in terms of drops in rankings is extremely detrimental for our business.

[Kurt_Steinbrueck]

PixelKicks gave a good answer.

In theory you shouldn't see much, if any, change in rankings, but in practice, any time you move pages, there is some risk.  I don't know if you can do a slow migration or not, but if you can, I'd suggest you do the following.

Start small:
Move a portion of the pages (maybe a couple hundred thousand for your big site) first, track their traffic and ranking and see if there is any impact.  I'd probably watch the pages for 3-4 weeks just to make sure.  If you see a drop, you may want to keep watching them longer to see if it comes back on its own.  This should give you an indication of what to expect for the other pages.

Setup Canonical Tags First
If you are able, setup the new pages (or entire new site) and then add canonical tags to all the old pages, pointing to the new pages.  This will actually start the transition process for Google and others and you may see the pages with canonical tags having been switched in Google in just a few days.  After you have seen that most or all the pages have been switched in Google, then setup the 301 redirects.

You can see Rand talking about this process in the video on this page: http://moz.com/blog/cross-domain-canonical-the-new-301-whiteboard-friday

How Long to Recover:
You may not see any drop in rankings.  You may see a little shifting for a few days, but then everything settles back to where it was.  If you do see a drop, it's likely that it will recover after a few weeks or months (as PixelKicks indicated).  If, on the other hand, you see a drop and it doesn't self-correct after several weeks, then the recovery is a matter of having to rebuild some authority to your site.  The time that will take will depend on how much work you put in to doing that and what your competition is like.

Good luck.  That's a huge site.

Kurt Steinbrueck
OurChurch.Com

[PixelKicks]

301's will pass "most" of the value, typically 90%, and you shouldn't see any long term impact from this. However you might notice a bit of short-term action from the changes, particuarly as you have around 15 million pages indexed. Whats the website? Will be interesting to take a look.

I don't think anyone can honestly say what the exact impact will be, but large sites do undergo changes such as what you mention, and you rarely hear reports of long-term pain. As long as you make sure that everything is correctly redirected then you probably won't notice much of a difference.

If you pushed for a definitive answer though I'd estimate within 3 months everything should be steady and back to normal again, and from then onwards you can judge whether the additional keywords have had any impact.

Cheers.