I was working with the completer example( that comes with Qt installation; C:\Qt\Qt5.3.0\Examples\Qt-5.3\widgets\tools\completer). It was working fine for the small text file wordlist.txt.But if I change wordlist.txt file with a textfile which has 200k words then there are significant delay in the popup completion box showing up. How do I remove this delay and show up the popup box instantly?( I need to show only 100 results in the popup box in every keystrokes in the QLineEdit.