Online communities: how to tell if one is still alive

The single most useful thing to know about any online community is whether people are still posting in it, and that is the thing community sites are least forthcoming about. Member counts are cumulative and include every account created since launch, most of which were abandoned years ago. They tell you nothing about activity.

What does tell you something: the date on the most recent substantive thread, the number of replies rather than views, and whether moderators have posted in the last month. A forum with two hundred thousand members and a last reply from eight months ago is an archive, not a community. Archives have real value, but they will not answer your question.

The other thing worth checking before investing time is whether the community is exportable. Platforms close, and communities that live entirely inside a proprietary system lose their history when the system shuts down. Forums that keep public, indexable archives tend to survive their platforms.

The listings below include both general platforms and smaller subject-specific communities. The smaller ones are usually where the expertise is, for the same reason specialist sites beat general ones everywhere else on the web.