CKEditor 4 has features found in desktop word processors such as styles formatting (bold, italic, underline, bulleted and numbered lists), tables, block quoting, web resource linking, safe undo function, image inserting, paste from Word and other common HTML formatting tools. Also CKEditor 4 has built-in spell checker functionality provided as plug-ins by WebSpellChecker LLC. By default, it is available for free with a banner ad.] It checks the spelling of the text and marks all errors with a red wavy line and allows the user to choose one of the correct suggestions.