Speed up browser showing changes


I had a nightmare recently where files that I uploaded by FTP looked ok at first but were actually incorrect.

They looked ok at first because it seems there is a delay between file upload and when the changes are shown.

I’ve tried hard resets and cache clearance but nothing seems to show the changes immediately.
I guess it has something to do with propagation.

Is there a developer tool to speed this up?
Is this something to do with the FTP client or the webhosts?