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. While the cost means you would only ever use this app if you’re a serious coder, what it does, it does very well. (Upgrading from BBEdit 11 is $29.99, or $39.99 to upgrade from earlier versions.) At that price point, BBEdit 12 delivers a huge array of features and works with Git, HTML, FTP, AppleScript, Mac OS X Unix scripting and a whole host of other neat tricks. BBEdit12 is compatible with macOS 10.12.6 and higher, and costs $49.99. BBEdit 12 is the premium alternative to Notepad++ for Mac and is intended for serious writers, software developers, and website coders.