Apple - Omnikey for Safari 13?
I was totally bugged out by the lack of Omnikey after upgrading to Safari 13. This applescript saved my life (it's not mine so I'm just posting the link): https://macscripter.net/viewtopic.php?id=47107
In order to activate it, open Automator, create a new Quick Action, select "Run Applescript" from the action list on the left side of the window, and copy/paste the script to the editor window. Above the editor window, change "Workflow receives" to "no input" and save.
Then go to System Preferences, keyboard, shortcuts, and assign a keyboard shortcut to it. Now, when in Safari's address bar you can just press the shortcut and the script transforms the search to the right URL, e.g. type "we apple", press the shortcut, services, and the wikipedia article about "Apple" opens in the same Safari tab.
In order to add more searches, just edit the script in the "property shortcuts" section, it looks pretty self-explanatory to me. Now searching from the address bar works almost as before, just have to get used to pressing the shortcut instead of return.
As OP informed, restarting after reverting using backup restore made Safari accept the Omnikey as an extension. They are on Safari 12.1.2.
The post below may concern those looking for more ways to achieve the same.
Omnikey can be used in the browser by fooling the browser (Safari 12.1.1) into believing that you're developing the extension(that's what I can make of it).
Load it using Show extension builder in Develop menu in the form of an folder which you can get by expanding the .xar version of the extension file which you can get from the site. Note that to get .xar from extension file, simply use rename feature.
Then just hit run. For details about updating previous preferences, or understanding it in more clarity, see original post by georgegarside at
https://georgegarside.com/blog/macos/install-any-safari-extension-macos-mojave/
But for alternatives:
Safari has inbuilt Quick Website Search, you just have to figure out the term that triggers it. Find out more in Safari Preferences → Search tab → Quick Website Search. Results are like this.
Use DuckDuckGo's !bangs .
A search for !w filter bubble will take you directly to Wikipedia. [...] and you can even submit your own.
source:https://duckduckgo.com/bang
https://computers.tutsplus.com/tutorials/how-to-set-up-custom-searches-in-safari--cms-26139 explains in detail those alternates that I figured out.
I was missing this very same functionality. In response, I created a small extension for Safari 14, replacing this functionality: Smart Keyword Search.
(I did today also stumble upon another extension claiming to do the same: Search Key -- I do feel that Smart Keyword Search allows for more options, and has better documentation, but I cannot be considered objective I guess :)).