I have a client that's launching a new website on their current domain.  I don't want to lose their SEO rankings, so I need to ensure that all the old, indexed content gets properly redirected to the new site when it launches.Is there a way to get the search index from Google so that no links are missed in the relaunch?  There is no sitemap, but I do have a Google Analytics account.
Is there a way to download the Google index for my website?
seo;google;301 redirect
When involved from the startWhen migrating I keep the existing URLs in mind right from the start of the project. Like that I already have most links covered when switching.Right after the switch I check site:example.com and see if most links there are still working. If a lot are failing I go through them manually if there are less than say 300.In the weeks and months after the switch I keep an eye on Google Webmaster to find broken URLs.When coming in laterIf I would not be involved in the migration from the start and I'd have doubts I'd probably write some code in Python (e.g. with Selenium) or CoffeeScript to either parse the result of a Google query on site:example.com or work with the logs from the webserver. If you have logs for a couple of months that will probably cover 99% of the URLs indexed by Google.Whatever is indexed by Google will be checked by Google regularly. If you have logs for the past years you can simply grep on Googlebot to get a list of all URLs accessed by Google. This can get you started: zcat access*.log*|awk '{ print $2 }'|sort|uniq (probably needs some sed and a different $n for awk).Of course I'd first check if such code is already available under a free license.Naturally I'd still check Google Webmaster and run the site:example.com query manually as described above.