A Visual Studio Extension that helps to extract inline styles into a separate css file. 

Available on Visual Studio Marketplace

https://marketplace.visualstudio.com/items?itemName=SuatKOSE.InlineStyleParserforHtmlFiles

Supporting .html, .aspx and .cshtml file formats.

Just right click on a html file source code and extract all inline styles into a separate css file. See the attached screenshots below.

Please let me know if you realize that something is wrong.

Thank you.

1-Sample Html

2-After Extracting Inline Styles

 3-Created .css File