I counted every subreddit since 2005, and "how many" depends on one definition

If you've ever tried to answer "how many subreddits are there?", you know the numbers online don't agree with each other. I wanted to know why, so I ran the count myself on every public Reddit post and comment going back to the start. The answer I got wasn't one number. It was three, and the gap between them is huge.

Here's what the same platform looks like through three different definitions:

You can quote any row of that table and be technically right. That's the part I find interesting as someone who works with data, because the hard question isn't the counting at all. It's deciding what you're counting before you write the first query.

What I counted as "active"

I'll walk you through the definitions, because they change everything downstream.

A subreddit exists in my data if it got at least one public post at any point, whatever its state is today. Banned, private or abandoned, it still counts. That's why the "ever" number only goes up, since dead subreddits don't get deleted and so they never leave the total.

A subreddit is active in a month if anyone posted or commented in it that month, in UTC. One comment is enough. I kept that bar low on purpose, but it also means a single spam post can make a community look alive.

So I added a stricter tier. Two, actually. For the 10+ and 100+ counts, I look only at posts, not comments, and only at accounts that aren't on my list of known bots. If you want to know how many communities people actually use, this is the number I'd trust.

There's one more thing I left out, and it's the biggest trap of all. Every Reddit account has a profile page you can post to, and under the hood it works like a small subreddit named u_ plus the username. In September 2026, more of those had a post than all the real communities combined. A count that includes them looks much bigger, so check for that before you trust anyone's total, including mine. Mine leaves them out.

Here's how the tiers moved, month by month:

Communities with a post or comment, and with 10+ or 100+ posts by people, January 2008 to September 2026. Profile pages excluded, and known bots don't count toward 10+ and 100+.

Why the strict filter matters

The loose count peaked in July 2023 and has dropped 21% since then. If you stopped reading the chart there, you'd write a "Reddit is shrinking" headline and move on. That'd be wrong.

But the busy communities held up, and that's the part the loose count hides. Subreddits with 100 or more posts by people grew by a third over the same stretch. What shrank is the long tail, the communities with a post but fewer than 10 posts by people:

The spikes on the chart tell the same story from the other side. Around the turn of 2016, the loose count went from 85,583 to 155,881 in five months and then fell most of the way back. Most of the extra communities had only a few posts each, and many had random-letter names or ads for sports live streams. That looks a lot like spam to me. Meanwhile the 10+ line barely moved. Without the filter, you'd read a spam wave as growth.

Even Reddit's own IPO filing said "over 100,000 active communities" without saying what active meant. My closest measure, 10 or more posts by people, was 110,339 in January 2024. That's the closest match I have, and it only works with the strict definition.

Most subreddits don't last

The other thing that surprised me is how short-lived most of them are. I count a subreddit as new in the year of its first post. By that measure, 2023 was the record year, with more new subreddits than any year before or since.

Of the 2023 crop, only 60,049 had a post in the last 12 months. Out of everything that ever had a post, 30% had exactly one. It's true that Reddit has millions of communities. It's also true that most of them are empty rooms. Both are fair, but they're not the same claim.

What this data can't tell you

I want to be upfront about the blind spots, because you'll run into them if you reuse any of this:

• Readers. Activity means posts and comments. Lots of people only read, and I can't see them.
• Empty and private subreddits. If a subreddit never got a post, it's invisible to me. So my "ever" number is lower than the number ever created.
• January 2026. It's missing from the monthly series, because subreddits with posts that month don't have names in my data yet.
• Bots. My bot list doesn't catch every bot, so a few automated communities still count as used.

Where to get the data

The full study has the method, the charts and the CSV files, free to reuse with credit. If you just want the current headline numbers, I keep live numbers, refreshed monthly. And if you want one subreddit's activity in the same terms, that's where the data comes from.

If you'd define "active" differently, I'd honestly like to hear how. It's the kind of choice that's worth arguing about.

I wrote this with AI help from my own dataset; every number is from the full study.