John Mueller of Google confirmed what most of you SEOs already know, that it can take Google “several months” to understand quality changes that are made to a site. John Mueller said on Twitter “making significant quality changes across a site takes time to be picked up & reflected in search.” “These things often take several months to be reprocessed & reevaluated,” he said.

John Mueller has said this before that while algorithm updates may impact a site quickly, it can take a while for the fixes you make be seen in Google. John said then “it’s more a matter of like maybe several months over which it takes for us to recrawl, re-index, reprocess the website to understand how it has changed, how we we need to change how we show it in the search results.”

Of course, you all know the painful wait process for a site after it gets negatively impacted by a core update. Often you need wait for another core update to see a full recovery and those now take several months (except for the last one).

Here is John’s new tweet on how long it takes Google to find the quality changes on your site:

Forum discussion at Twitter.