301 as soon as the new page is active, you don't want to let Google think that there are '000s of copies of your pages 'floating' around.
So how does Google react when you suddenly 301 a crapload of pages, say 20,000 - 85,000? I remember doing that before and feeling that Google took a good few months to catch up and while it was, our number of listed pages and rankings fluctuated wildly.
It starts throwing things into the index, then throwing them out again. In, out, in, out, shake it all about. :)
I stuffed something up the other day, which led to a whole load of 'extra' URLs leading to the same pages. I swear they were only visible for minutes, but Google (darn it) found them and now I'm watching the supps index change by the hour while I frantically try and 301 the 'extras' to a single, correct URL.
Moral of the story: If there's a possibility of an incorrect URL causing 'duplicate' issues, Google WILL find it. MSN and Yahoo seem to stick fairly rigidly to the sitemap, while Google goes walkabout. 301 asap.
I just upgraded a site to new software and had to change all the urls. There were only about 400 and so far I have not had any problem. I unblocked from robots text the new urls and put the redirects up at the same time. All the new pages are drifting into the index now.
They will start to list some of the new URLs quite quickly, but getting most of them listed will take at least 6 months. Some might not make it.
Many of the old URLs will remain in the index for many months, maybe even a year. Your redirect will get the visitor to the correct content anyway.
Once any of the old URLs are shown as Supplemental Results you cannot control what Google will show for those. Ignore them and move on. Google will do what it has to do from then on.
Many of the old URLs will remain in the index for many months, maybe even a year.
They will appear as Supplemental results.
Let me ask a variation on this question...
When redirecting "index.html" to "/", would you wait until after Google has seen (or cached) the changed links in your nav, or would you apply the redirect as soon as the nav change is made?
My instinct had been to apply the redirect immediately, but I've discussed this with those who feel that, in this case, Google should see the changed link before the redirect.
Their thinking is that you don't want Google believing you're linking to one url of a page while you're redirecting to another. As Google already sees more than one url for the page, I assume the redirect timing isn't going to change the dupe issue, and that it's more a question of consistency in Google's eyes, if that's something Google weighs.
[edited by: Robert_Charlton at 2:31 am (utc) on May 3, 2007]
They will revisit the URLs that are listed in their database, whether or not you link to them.
You do not need to wait for them.
|They will revisit the URLs that are listed in their database, whether or not you link to them. |
Thanks. I'm quoting your comment again, because it answers a lot of questions.