You will see Editor Preferences dialog when you want to add or edit editor from Editors page of Preferences dialog.
Learn how to configure some popular editors.
When you want to use external editor, you need to specify local path to its executable. Use Browse button to locate the executable. When typing path manually do not forget to add quotes around path containing spaces. If you need you may specify a command-line parameters for your editor. Use pattern
!.! to specify where should WinSCP place name of the file to edit (quotes around filename containing spaces are added automatically).
Use button Use default system editor to make WinSCP detect editor associated with text files (
If you want use different editors for different file-types, specify file mask matching file(s) (or file-types) to be associated with the particular editor. The first editor, whose autoselection mask matches name of edited file, will be used. The order of editors is defined on Editors page of Preferences dialog.
The External editor opens each file in separate window (process) checkbox disables special behavior needed to support editors that open multiple files in one window.
The Force text transfer mode for files edited in external editor checkbox forces text transfer mode for transfers to/from external editor. When unchecked the configured transfer mode will be used (binary by default). You typically need to use the option only when the server does not support format of text files used by the server. Most modern text editors support all common formats of text file. A notable exception is Windows Notepad until until Windows 10 1809. Learn more about editing binary files in an external editor. Note that text mode is always forced for an internal editor.
Options for internal editor are global (configured on Internal Editor page of Preferences dialog).