People over the years have complained a lot about the reports within Google Search Console. Some don't trust the reports, some are confused why some other analytics tool do not align and over the years we reported on many glitches and outages. But there is really no other tool that has access to Google data as Google has access to it. Google knows when they serve up your site in the search results, they know better when someone clicks on your results, when it gets an impression and what keywords people are searching for to return your site in search.
We can only access that type of data via their Search Analytics API or try to do it via scraping but then you have the localization impacts and personalization impacts not taken into account.
John Mueller of Google said on Twitter that Google Search Console reports are "as accurate as it gets."
Here are the tweets:
Sure; it's as accurate as it gets.
— John ☆.o(≧▽≦)o.☆ (@JohnMu) July 11, 2018
This type of saying means it doesn't get more accurate but being that John's native language is not English, I am not 100% sure if he means that. But John's english is extremely good. :)
Forum discussion at Twitter.
