@T.I-Digital-Solutions said:
I mainly use Notepad++ for working with HTML, checking page source, and making quick edits during SEO tasks, so I was curious about features that could make those jobs easier.
With those specifics, then I’d say good plugins to try would be HTML Tag, Preview HTML, and XMLTools.
UDL is not useful for HTML, because the HTML lexer that’s built into Notepad++ is better than anything that the simple User Defined Language system can handle. But if you also deal with the server configuration files (like .htaccess files), then the UDL Collection has a UDL available for Htaccess, for example.