The details of site preparation vary for each site move, but typically you’ll do one or more of the following:

• Set up a new content management system (CMS) and add content to it.
• Transfer images and downloads (such as PDF documents) you currently host.
  These might already be getting traffic from search results or links, and it’s useful to tell users and Googlebot about their new location.
• For a move to HTTPS, get and configure the required TLS certificates on your server.

The rest of the article covers specific task we recommend when prepping your new site.

Set up a robots.txt for your new site

The robots.txt file for a site controls which areas Googlebot can crawl. Make sure the directives in the new site’s robots.txt file correctly reflect the parts you want blocked from crawling.

Note that some site owners block all crawling while in development. If you follow this strategy, make sure you prepare what the robots.txt file should look like once the site move starts. Likewise, if you use noindex directives during development, prepare a list of URLs from which you’ll remove the noindex directives when you start the site move.

Provide errors for deleted or merged content

For content on the old site that will not be transferred to the new site, make sure those orphaned URLs correctly return an HTTP 404 or 410 error response code. You can return the error response code at the source URL in the configuration panel for your new site, or you can create a redirect for a new destination URL and have that return the HTTP error code.

Ensure correct Search Console settings

A successful site move depends on correct—and up to date—Search Console settings.

If you haven’t already, verify you own both the old and destination sites in Search Console. Be sure to verify all variants of both the source and destination sites. For example, you should verify www.example.com and example.com, and include both the HTTPS and HTTP site variants if you use HTTPS URLs. Do this for both source and destination sites.

Review the Search Console verification

Make sure your Search Console verification will continue to work after the site move. If you're using a different method of verification, keep in mind that verification tokens may be different when the URL changes.

If you’re using the HTML file method to verify ownership of your site in Search Console, make sure you don’t forget to include your current verification file in your new copy of the site.

Likewise, if you verify ownership with an include file that references meta tag or uses Google Analytics to verify ownership, ensure the new CMS copy includes these as well.

Review any configured settings in Search Console

If you had changed some of the configuration settings in Search Console for your old site, make sure the new site’s settings are updated to reflect those changes as well. For example:

• URL parameters: If you’ve configured URL parameters to control the crawling or indexing of your old URLs, make sure the settings are also applied to the new site if needed.

• Geotargeting: Your old site might have explicit geotargeting, such as a geotargetable domain or a country-coded top-level domain (such as .co.uk). Apply the same setting to the new site if you want to continue targeting for the same region. However, if your site move is meant to help your business expand globally and you do not wish your site to be associated with any country or region, select Unlisted in the drop-down list of the Site Settings page.

• Crawl rate: We recommend not limiting Googlebot’s crawl rate in Search Console for both source and destination URLs.  We advise you don’t configure a crawl rate setting, either. Only do this if you know that your site cannot handle Googlebot’s volume of crawling. If you have already limited Googlebot’s crawl rate for your old site, consider removing it.  Google has algorithms that automatically detect that a site move has been implemented and we alter Googlebot’s crawling behavior so that our indexing quickly reflects the site move.

• Disavowed backlinks: If you’ve uploaded a file to disavow links on your old site, we recommend you re-upload it again using the Search Console account of the new site.

Clean up your recently purchased domain

If your new site is for a recently purchased domain, you'll want to make sure it's clean of any outstanding issues from the previous owner. Check the following settings:

• Manual action for previous spam. For sites that do not comply with our Webmaster Guidelines, Google is willing to take manual action, such as demoting them or even removing them from our search results altogether. Check the Manual Actions page in Search Console to see if any manual actions have been applied to the new site, and address any problems listed there before filing a reconsideration request.
• Removed URLs. Make sure there aren’t any URL removals left over from the previous owner, especially a site-wide URL removal. Also, before submitting URL removal requests for your content, make sure you understand when not to use the URL removals tool.

Use web analytics

During a site move, it’s important to analyze usage on both the old and new sites. Web analytics software can help with this. Typically, web analytics configuration consists of a piece of JavaScript embedded in your pages. The details for tracking different sites varies depending on your analytics software and its logging, processing, or filtering settings. Check with your analytics software provider for help. Additionally, if you have been planning to make any configuration changes to your analytics software, now is a good time. If you use Google Analytics, consider creating a new profile for your new site if you want clean separation in your content reports.

Ensure serving resources in your new domain

After a migration, Google will crawl your new site more heavily than usual. This is because your site redirects traffic from the old to the new site, and any crawls of the old site will be redirected to the new site, in addition to any other crawling. Ensure that your new site has sufficient host load to handle the increased traffic from Google.

Update Data Highlighter

If you used Data Highlighter to map your old pages, be sure to redo the mapping for your new site.

Update app links

As soon as your HTTPS pages are ready, update any app links intended to open your web pages in an app when displayed in Google Search results. Update these links to point to the new HTTPS URLs. Redirects won't work for these links; mobile browser clicks will open the page in the browser instead of the app unless you update your app link handling.

* Nguồn: Google Search Console