[eref]

For me on Firefox on macOS that is just a couple of key strokes away:

  cmd-l cmd-c ctrl-a r <space> u r l : <enter> cmd-t cmd-v ctrl-a h n <enter>

I have set up `r` as keyword to search on Reddit and `hn` to search on Hacker News [1]. `url:` is the Reddit keyword to search in the url field of the items. (In Firefox, you can right click any search field and add a keyword bookmark for it.)

[1] https://hn.algolia.com

[dredmorbius]

DDG (from the browser navbar) functions in much the same way.

!hn => hacker news

!se => stack exchange

!w => wikipedia

!r => reddit

(Not all of these are forums, natch.)