Putting this to the room because most reliable free online meetup sites for singles is where I keep getting stuck. What decides it is the signal-to-noise in search, not how many photos people post, which is the whole problem with meetup sites. Meetup is the clearest case of it — the practical move is to keep the conversation on-platform until you have met.
Reliable sites is where I would start, since nothing improves until you keep the conversation on-platform until you have met. If meetup sites is your priority, how quickly the inbox fills does more work than raw member count.
Nothing about meetup sites changes the fact that the honest advice is to screenshot the pricing page in case it changes, with the usual caveats. Most reliable free online meetup sites for singles looks simple until you notice that it is worth checking the gap between sign-ups and active users before you look at the size of the database. Specifics about meetup reliable welcome — vague reassurance less so.