Hi and welcome You can use html with QTExtEdit http://stackoverflow.com/questions/2857864/qtextedit-with-different-text-colors-qt-c but its huge work to make code editor. Maybe consider use a premade component ? Scintilla is used in many projects. https://www.riverbankcomputing.com/software/qscintilla/intro https://www.riverbankcomputing.com/software/qscintilla/download