Confluence stores all page data in Confluence's wiki markup syntax. Importing non-wiki markup into Confluence requires a conversion process.

• Text with basic formatting can be pasted directly into the Rich Text Editor. This includes simple Word documents or web pages.
• Files such as Microsoft Word and Excel documents can be imported using a Content Converter
• Confluence pages saved to disk can be Imported From Disk

For web content:

• Convert a HTML file to a Confluence page using the HTML To Confluence Converter
• Embed an external web page into Confluence with the Html-include Macro
• Use HTML code in a page with the HTML Macro

For other wikis:

• Check if the Universal Wiki Converter can import it