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Type: boolean
If true, spell checking is enabled by default for the text box; if false, spell checking is disabled by default.
If not specified, this defaults to false


The spellcheck attribute uses values of true or false (you cannot simply add the spellcheck attribute to a given element):

<!-- spellcheck everything! -->
<input type="text" spellcheck="true" /><br />
<textarea spellcheck="true"></textarea>
<div contenteditable="true" spellcheck="true">I am some content</div>

<!-- spellcheck nothing! -->
<input type="text" spellcheck="false" /><br />
<textarea spellcheck="false"></textarea>
<div contenteditable="true" spellcheck="false">I am some content</div>

You can use spellcheck on INPUTTEXTAREA, and contenteditable elements.  Thespellcheck attribute works well paired with the autocomplete, autocapitalize, and autocorrect attributes too!

Added from David Walsh's article on Spell Check.