Indexed pages data from Webmaster tools not matching with site:xyz.com

[zentrader99]

For one of my, site:xyz.com gives 20K results in Google. But webmaster tools show 75K pages indexed.
Which one is more accurate?

 

[Steptoe]

The site: operator provides an estimate at best. GSC should be more accurate, but then again this is Google we're talking about

 

[Ryuzaki]

The most accurate data provided to us lies within Search Console in the Coverage Report. The site: operator has never been a full list of indexed pages, though it closely correlates for the most part.

 

[zentrader99]

The most accurate data provided to us lies within Search Console in the Coverage Report. The site: operator has never been a full list of indexed pages, though it closely correlates for the most part.

In my case, it is off by a wide margin. Actually, in this case, it varies by 400%. My search console shows 75K indexed (which is almost 80-90% of my total pages) but the site:xyz.com operator gives around 17K results.