If you have “confirmation” pages that users reach only after they have completed an important action, it’s a best practice to noindex these pages. Why?
Let’s say each time someone reaches the /thank-you/ page, you count that as a goal completion in Google Analytics. If a user finds that page in Google’s search results and visits it, this would count as a conversion in Google Analytics. And if you multiply that by many unique searchers, these visits now all count as a conversions in Google Analytics and severely skew your conversion data.
For this reason, it’s recommended that you noindex pages like these:
- Confirmation pages
- Thank you pages
- Contact form redirect pages
- Paid landing pages
You can look in Google’s SERPs to see if any conversion pages or landing pages are indexed using search operators like this: