There are many alternatives to Google Keep for Mac if you are looking for a replacement. The best Mac alternative is NoteLedge. It's not free, so if you're looking for a free alternative, you could try Standard Notes or Microsoft OneNote. If that doesn't suit you, our users have ranked more than 100 alternatives to Google Keep and loads of them are available for Mac so hopefully you can find a suitable replacement. Other interesting Mac alternatives to Google Keep are Joplin (Free Personal, Open Source), Obsidian (Free Personal), Simplenote (Free, Open Source) and Evernote (Freemium).
File system notes is modern notes manager on steroids for macOS and iOS. Application respects open formats: plain/text, markdown, rtf, and stores data in file system. You can view, edit, copy data in favourite external editor and see live results in FSNotes.
NoteAway is the simplest, most convenient way to take quick notes on OS X. NoteAway has lots of powerful features for free, like iCloud syncing, rich text, attachments, simple import/export, and a variety of customizable options.
Allegory is a powerful notes app with a beautiful iOS-centric UI. The minimal and focused writing experience, combined with an impressive set of powerful features, makes this the ideal choice for everyone.