Let's say you use WordPress editor, or other online web forms. Even if you don't use an Editor plugin like Tiny MCE Advanced, you can still have real-time as-you-type spell checking. You may find that the proper setting to enable Chrome's spell checking is turned off.
If you notice that Chrome isn't putting little squiggly lines below misspelled words as you type, it's a quick fix to resolve this. Here's the exact steps, note, no Chrome extension required!
1) in Chrome, click the 3 little horizontal bars at top-right
2) choose 'Settings'
3) scroll all the way down to the bottom, and click 'Show advanced settings...'
4) ensure the checkbox is on for 'Use a web service to help resolve spelling errors'
5) in a blank area of a web page's text input area, right-click, choose 'Spell-checker options' and make sure checkbox is on for both 'Check the spelling of text fields' and
6) 'Ask Google for suggestions'
7) that's all, misspelled words should immediately now show a squiggly red underline
All about this feature in Google's article, Chrome's privacy settings:
Use a web service to help resolve spelling errors
- About this feature: This allows Chrome to use the same spell-checking technology as Google Search. To enable this feature, right-click inside the text field that you're typing in and select Spell-checker options & Ask Google for suggestions.
- Information that is sent: When this feature is enabled, Chrome will send the text you typed to Google’s servers.
- Learn more about Google Search's spell-checking technology