Copy difference from right side to left side and select next difference

`Ctrl` + `Alt` + `←`

All hotkeys for WinMerge

Comparing folders Open selected file or folder	`⤶ Enter`
Comparing folders Open parent folder if possible (available only when subfolders are not included in compare)	`⬅ Backspace`
Comparing files Refresh	`F5`
Difference navigation and merging (normal mode) Go to first difference	`Alt` + `Home`
Difference navigation and merging (normal mode) Go to last difference	`Alt` + `End`
Difference navigation and merging (normal mode) Go to current difference or select difference	`Alt` + `⤶ Enter`
Difference navigation and merging (normal mode) Go to previous difference	`Alt` + `↑`
Difference navigation and merging (normal mode) Go to next difference	`Alt` + `↓`
Difference navigation and merging (normal mode) Copy difference from right side to left side	`Alt` + `←`
Difference navigation and merging (normal mode) Copy difference from left side to right side	`Alt` + `→`
Comparing files Close window (if enabled in options)	`Esc`
Comparing files Show line difference	`F4`
Comparing files Change pane (active file)	`F6`
Comparing files Go to previous difference	`F7`
Comparing files Go to next difference	`F8`
Comparing files Merge Mode on or off (toggle)	`F9`
Comparing files Go to difference or line	`Ctrl` + `G`
Comparing files Undo last action	`Ctrl` + `Z`
Comparing files Redo previously undone action	`Ctrl` + `Y`
Difference navigation and merging (merge mode) Copy difference from right side to left side and select next difference	`Ctrl` + `Alt` + `←`
Difference navigation and merging (merge mode) Copy difference from left side to right side and select next difference	`Ctrl` + `Alt` + `→`
Difference navigation and merging (merge mode) Go to previous difference	`↑`
Difference navigation and merging (merge mode) Go to next difference	`↓`
Difference navigation and merging (merge mode) Copy difference from right side to left side	`←`
Difference navigation and merging (merge mode) Copy difference from left side to right side	`→`
Find and replace Find text (opens Find dialog)	`Ctrl` + `F`
Find and replace Replace text (opens Replace dialog)	`Ctrl` + `H`
Find and replace Find next	`F3`
Find and replace Find previous	`↑ Shift` + `F3`
Find and replace Find selected text in file	`Ctrl` + `F3`
Find and replace Find selected text upwards in file	`Ctrl` + `↑ Shift` + `F3`
Bookmarks Toggle Bookmark	`Ctrl` + `F2`
Bookmarks Next Bookmark	`F2`
Bookmarks Previous Bookmark	`↑ Shift` + `F2`
Bookmarks Clear all Bookmarks	`Ctrl` + `↑ Shift` + `F2`
Bookmarks Goto Bookmark 0	`Alt` + `0`
Bookmarks Toggle Bookmark 0	`Ctrl` + `0`
Bookmarks Goto Bookmark 1	`Alt` + `1`
Bookmarks Toggle Bookmark 1	`Ctrl` + `1`
Bookmarks Goto Bookmark 2	`Alt` + `2`
Bookmarks Toggle Bookmark 2	`Ctrl` + `2`
Bookmarks Goto Bookmark 3	`Alt` + `3`
Bookmarks Toggle Bookmark 3	`Ctrl` + `3`
Bookmarks Goto Bookmark 4	`Alt` + `4`
Bookmarks Toggle Bookmark 4	`Ctrl` + `4`
Bookmarks Goto Bookmark 5	`Alt` + `5`
Bookmarks Toggle Bookmark 5	`Ctrl` + `5`
Bookmarks Goto Bookmark 6	`Alt` + `6`
Bookmarks Toggle Bookmark 6	`Ctrl` + `6`
Bookmarks Goto Bookmark 7	`Alt` + `7`
Bookmarks Toggle Bookmark 7	`Ctrl` + `7`
Bookmarks Goto Bookmark 8	`Alt` + `8`
Bookmarks Toggle Bookmark 8	`Ctrl` + `8`
Bookmarks Goto Bookmark 9	`Alt` + `9`
Bookmarks Toggle Bookmark 9	`Ctrl` + `9`
Zoom Increase text size	`Ctrl` + `+`
Zoom Decrease text size	`Ctrl` + `-`
Zoom Reset text zoom to default size	`Ctrl` + `*`
Zoom Increase text size	`Ctrl` + `Mouse wheel up`
Zoom Decrease text size	`Ctrl` + `Mouse wheel down`