On graphical displays, each Emacs window normally has narrow fringes (gutters/margins) on the left and right edges. The fringes are used to display symbols that provide information about the text in the window. You can type M-x fringe-mode to disable the fringes, or modify their width. This command affects fringes in all frames; to modify fringes on the selected frame only, use M-x set-fringe-style . You can make your changes to the fringes permanent by customizing the variable fringe-mode .

Out-of-the-box the most common use of the fringes is to indicate a continuation line. When one line of text is split into multiple screen lines, the left fringe shows a curving arrow for each screen line except the first, indicating that “this is not the real beginning”. The right fringe shows a curving arrow for each screen line except the last, indicating that “this is not the real end”. If the line’s direction is right-to-left, the meanings of the curving arrows in the fringes are swapped.

Third-party modes like flycheck and diff-hl also make use of the fringe to display valuable information there (e.g. lint and VC information).

By default both fringes have width 8 pixels, but we can easily adjust this:

;; make both fringes 4 pixels wide ( fringe-mode 4 ) ;; make the left fringe 4 pixels wide and the right disappear ( fringe-mode ' ( 4 . 0 )) ;; restore the default sizes ( fringe-mode nil )

As mentioned before, you can also invoke this command interactively and determine the optimal fringe size for you, before making it permanent in your config. The options presented by the fring-mode command are defined in the fringe-styles list:

( defconst fringe-styles ' (( "default" . nil ) ( "no-fringes" . 0 ) ( "right-only" . ( 0 . nil )) ( "left-only" . ( nil . 0 )) ( "half-width" . ( 4 . 4 )) ( "minimal" . ( 1 . 1 ))) "Alist mapping fringe mode names to fringe widths. Each list element has the form (NAME . WIDTH), where NAME is a mnemonic fringe mode name and WIDTH is one of the following: - nil, which means the default width (8 pixels). - a cons cell (LEFT . RIGHT), where LEFT and RIGHT are respectively the left and right fringe widths in pixels, or nil (meaning the default width). - a single integer, which specifies the pixel widths of both fringes." )

Be careful when playing with the fringe size. Certain info doesn’t look very good when the fringe is too small (e.g. less than 4 pixels).