There are times when may type a word wrongly while commenting on a website, leaving a comment on youtube or doing some thing else. Personally I use google as a spell check engine it always suggest the right word, now you can use the same google search spell check technology in google chrome as well for resolving these spelling mistakes you do.
You should know that Google uses spell checking software to check queries against common spellings of each word. Google determine an alternative query that it think might improve the search results, you’ll see "Did you mean: (more common spelling)" at the top of your search results page. For example, if you search for [ foot ball ], at the top of the search results page, you’ll see "Did you mean: football," a more common spelling of the game’s name
Enable Google Search Spell Check Technology in Google Chrome
You just need to right click a word which needs correction and then you will need to select the option which says ask google for spell check
Once you check this option you will be asked to enable this feature – you will need to click the enable button.
Once this feature is enabled, you will be this allows Google Chrome to use the same spell-checking technology as Google Search. To enable this feature, right-click a misspelled word and select Ask Google for Suggestion.
Note: When this feature is enabled, Chrome will send the misspelled text you typed to Google’s servers.
This way you will get the real time word count for any spelling mistakes you make while typing in google chrome. If you want to have a real time spell check and auto correction then you can use some google chrome extensions like Dictionary.com extension for google chrome which comes for free.