Sublime Text 3 is another alternative to Notepad++ that gets a lot of recommendations from whomever I ask. At $59 for a full single-user license, it isn’t cheap but again, if you live in text, this app has everything you could possibly need whether coding, building web pages or writing your next novel.
It requires macOS 10.9 or higher, but has search and replace, auto indent, auto pairing, a clipboard with history, column tools, multi-language support, CSS and HTML tools, foldable code blocks and a raft of other goodies. TextMate is a heavy hitter in terms of features.