The Red Squiggle Distraction
macOS comes with a robust, system-wide spell-checking engine that integrates into almost every native application, including Mail, Notes, Pages, and Safari. By default, as you type, this engine constantly evaluates your input against its built-in dictionary. If it detects a word it doesn’t recognize, it will automatically highlight it with a jagged red underline. While helpful for drafting formal emails, this feature is incredibly distracting if you are writing technical documentation filled with acronyms, drafting fantasy fiction with unique character names, or writing code snippets inside a rich-text editor, as your entire document will be covered in red “error” lines.
Turning Off the Spell Checker
To clean up your visual workspace and stop macOS from automatically highlighting misspelled words as you type, you must disable the background spelling check in the global Keyboard settings.
Because this setting controls the behavior across the entire operating system, you change it in the central System Settings. Click the Apple logo in the top-left corner of the screen and select System Settings (or System Preferences). In the left-hand navigation sidebar, scroll down and click on Keyboard. In the main panel, under the “Text Input” section, look for “Input Sources” and click the Edit… button next to it. A new dialogue window will appear. Look down the list of toggles for an option labeled Correct spelling automatically and ensure it is turned Off (to stop it from actively changing your words). Then, to remove the visual red lines, look for the dropdown menu labeled Check spelling. Change this setting from “While typing” to Never. Click “Done” to apply the changes system-wide.