Formatting code in Notepad++

Question

TextFX -> HTML Tidy -> Tidy: Reindent XML

Remember to have the HTML code selected before you do this.

there is such a plugin as UniversalIndentGUI, it can be installed right from the plugin manager and has possibilities to reindent the most used programming languages.

If you go to TextFX menu and go to TextFX Edit, you will see a menu item Reindent C++ Code.

That will also format C# code.

Here is a list of the available shortcuts in Notepad++.

In case your desired functionality is not available, you are able to define own macros and assign them to a custom shortcut (i am not used to use macros).

UPDATE: I will post the shortcuts here in case the link gets invalid:

Shortcut    Command

Ctrl-C  Copy
Ctrl-X  Cut
Ctrl-V  Paste
Ctrl-Z  Undo
Ctrl-Y  Redo
Ctrl-A  Select All
Ctrl-F  Launch Find Dialog
Ctrl-H  Launch Find / Replace Dialog
Ctrl-D  Duplicate Current Line
Ctrl-L  Delete Current Line
Ctrl-T  Switch the current line position with the previous line position
F3  Find Next
Shft-F3 Find Previous
Ctrl-Shft-F Find in Files
Ctrl-F3 Find (volatil) Next
Ctrl-Shft-F3    Find (volatil) Previous
Ctrl-Shft-I Incremental Search
Ctrl-S  Save File
Ctrl-Alt-S  Save As
Ctrl-Shft-S Save All
Ctrl-O  Open File
Ctrl-N  New File
Ctrl-F2 Toggle Bookmark
F2  Go To Next Bookmark 
Shft-F2 Go To Previous Bookmark
Ctrl-G  Launch GoToLine Dialog
Ctrl-W  Close Current Document
Alt-Shft-Arrow keys or Alt + Left mouse click   Column Mode Select
F5  Launch Run Dialog
Ctrl-Space  Launch CallTip ListBox
Alt-Space   Launch Word Completion ListBox
Tab (selection of several lines)    Insert Tabulation or Space (Indent)
Shft-Tab (selection of several lines)   Remove Tabulation or Space (outdent)
Ctrl-(Keypad-/Keypad+) or Ctrl + mouse wheel butto  Zoom in (+ or up) and Zoom out (- or down)
Ctrl-Keypad/    Restore the original size from zoom 
F11 Toggle Full Screen Mode
Ctrl-Tab    Next Document
Ctrl-Shft-Tab   Previous Document
Ctrl-Shft-Up    Move Current Line Up
Ctrl-Shft-Down  Move Current Line Down
Ctrl-Alt-F  Collapse the Current Level
Ctrl-Alt-Shft-F Uncollapse the Current Level
Alt-0   Fold All
Alt-(1~8)   Collapse the Level (1~8)
Alt-Shft-0  Unfold All
Alt-Shft-(1~8)  Uncollapse the Level (1~8)
Ctrl-BackSpace  Delete to start of word
Ctrl-Delete Delete to end of word
Ctrl-Shft-BackSpace Delete to start of line
Ctrl-Shft-Delete    Delete to end of line
Ctrl-U  Convert to lower case
Ctrl-Shft-U Convert to UPPER CASE
Ctrl-B  Go to matching brace
Ctrl-Shft-R Start to record /Stop recording the macro
Ctrl-Shft-P Play recorded macro
Ctrl-Q  Block comment/uncomment
Ctrl-Shft-Q Stream comment
Ctrl-Shft-T Copy current line to clipboard
Ctrl-P  Print
Alt-F4  Exit
Ctrl-I  Split Lines
Ctrl-J  Join Lines
Ctrl-Alt-R  Text Direction RTL
Ctrl-Alt-L  Text Direction LT
F1  About

The latest plugin is tidy2, which can be installed through Plugins>Plugin Manager>Show Plugin Manager.

I suggest editing config 1 and setting quote-marks: no, especially if you have script that makes use of quotes.

Also, tidying more than once can result in inserting ampersands the first time and then replacing the ampersands the second time. You may want to play with the config to get it to where you need it.

ANSWER AS OF June 2019

Install the XML Tools plugin from the Plugin Admin (in Notepad++ 7.7 at least)

Then click Plugins -> XML Tools -> Pretty Print (XML Only with Line breaks)

That did it for me.