The spell checker in the online editor is queried via the dictionaries installed in the browser. New words can be added to the dictionary easily and individually.
By default, automatic spell checking is enabled in Firefox. You can add as many dictionaries as you need.
For more information, such as correcting misspelled words or deleting a word that was added by mistake, see Firefox Help .
Chrome has an automatic spell checker that circles misspelled words in web forms in red. By right-clicking on a word marked in this way, Chrome shows you correction suggestions which you can accept with a single click. Or select "Add to dictionary" if the word is spelled correctly but not recognized by Chrome.
You can subsequently edit the user dictionary by clicking on the menu icon to the right of the address line. There, select "Settings", scroll all the way down the settings page, click "Show advanced settings", then "Language and input settings" and finally "Custom dictionary for spell checking". In the "Language and input settings" you can add additional languages if required. You can switch flexibly between languages by right-clicking in a web form field and navigating to "Spell Check Options" on the shortcut menu.
There you will also find the option "Suggestions from Google". If you enable it, Chrome will use the same powerful spell-checking feature that Google uses to eliminate spelling errors in searches. However, your input into web forms is sent to a Google server in the background.
To turn spell checking off completely, right-click in a text box and disable Spell Check Options > Check Spelling in Text Boxes.