Spell check web page if localhost, offline, in development, etc.

Spell checking website content before publishing is a must.  It will improve visitor trust and your reputation.  If you are using a site builder tool that incorporates a wysiwyg text editor, spell check is likely an included feature.  Also, most modern browsers spell check data entered into form fields and text areas automatically.  But what about when you're developing a site using HTML?  Most online web page spell checking services will require your site to be live (with a public URL) but that sort of defeats the best practice of "check first, then publish".  Fortunately, there's a Firefox add-on that will provide offline spell check for free: https://addons.mozilla.org/en-US/firefox/addon/spell-checker/

...now if only they could port it over to Chrome!