[jeffvogelsang]

Have a look at: https://github.com/el1t/uBlock-Safari. Available for download in the Safari extensions gallery.

[heavymark]

When installed, under settings for that plugin Safari shows a warning saying, "This extension will slow down your web browsing." Other content blockers such as 1Blocker do not show that warning by Apple.

[apple4ever]

I’ve tried using it, but its just not that great. The UI is pretty terrible and its really hard to unblock needed sites.