An online community is a group of people who gather in a digital space around a shared interest, identity, goal or need, and who interact with each other over time rather than simply consuming content. Online communities can live on forums, Discord servers, Facebook Groups, Slack workspaces, subreddits or dedicated community platforms, and they are defined by member to member interaction, shared norms and a sense of belonging.
What is an online community?
Ask ten people "what is an online community" and you will get ten slightly different answers. That is because the phrase covers everything from a 40 person Slack group for freelance illustrators to a subreddit with 60 million members.
The useful definition is behavioural rather than technical. An online community exists when three things are true at once:
- People share something. An interest, a profession, a life circumstance, a location, a product they use, or a goal they are working towards.
- People interact with each other. Not just with the host or the content. Members answer each other's questions, argue, collaborate and form relationships.
- Interaction persists. There is a history, a set of norms, and a reason to come back.
Remove any one of those and you have something else. A shared interest without interaction is an audience. Interaction without persistence is a conversation. Persistence without anything shared is a mailing list.
The psychology behind this is older than the internet. In their foundational 1986 paper, McMillan and Chavis described a "sense of community" as resting on four elements: membership, influence, integration and fulfilment of needs, and shared emotional connection. Those four elements translate almost perfectly to digital spaces, which is why the framework still gets cited by community professionals nearly four decades later.
Online communities in one sentence
Online communities are digital spaces where people with something in common talk to each other, not just to a brand or a broadcaster.
Online communities vs social media followings
This distinction trips up a lot of marketers, so it is worth being precise about it.
| Social media audience | Online community | |
|---|---|---|
| Direction of value | Creator to audience | Member to member |
| Ownership | Rented from the platform | Owned or governed by the host |
| Success metric | Reach, impressions, followers | Participation, retention, contribution |
| Discovery | Algorithmic | Intentional joining |
| Relationship | Parasocial | Reciprocal |
A brand with 500,000 Instagram followers has an audience. A brand where 4,000 of those people answer each other's questions in a forum has an online community. The second group is smaller and considerably more valuable, because the conversation continues whether or not the brand shows up that day.
The scale of the underlying opportunity is not in doubt. DataReportal's Digital 2026 data puts global internet users at 6.12 billion, equal to 73.8 percent of the world's population, with social media user identities reaching 5.79 billion in April 2026. Nearly everyone who is online is already in at least one group chat, forum or server.
The core characteristics of online communities
Healthy online communities tend to share a recognisable set of traits:
- A clear purpose. Members can explain in one sentence why the space exists.
- Defined membership. Even open communities have a boundary, whether that is a sign up, an application or simply an act of joining.
- Shared norms and rules. Written guidelines plus the unwritten culture that sits underneath them.
- Active moderation. Someone is responsible for enforcing standards and resolving conflict.
- Rituals and rhythms. Weekly threads, monthly calls, annual meetups, introduction posts.
- Recognition. Ways for contributors to gain status, whether through badges, roles, reputation points or simple public thanks.
- A core of committed members. A small group who show up consistently and set the tone for everyone else.
That last point deserves its own section, because it is the single most misunderstood thing about how online communities behave.
The 90-9-1 rule: how participation actually works
In 2006, Jakob Nielsen of Nielsen Norman Group described a pattern he called participation inequality. His summary: 90 percent of users are lurkers who read or observe but never contribute, 9 percent contribute occasionally, and 1 percent account for almost all of the activity.
Nielsen found the skew was even more extreme in some places. On Wikipedia, he noted that more than 99 percent of users were lurkers, with the most active 1,000 people producing roughly two thirds of all edits.
Two practical implications follow:
- Silence is not failure. If 90 percent of your members read without posting, your community is behaving like a normal human group. Lurkers still gain value, still develop loyalty and still convert.
- Protect the 1 percent. A small number of people carry the culture. Losing three or four of them can flatten a community that looked healthy on paper.
Smaller and more specialised online communities often outperform the ratio, with contribution rates closer to 70-20-10, but the curve itself almost never inverts.
Types of online communities
Most online communities fall into one of these categories, though many blend two or three.
1. Communities of interest
Built around a hobby, fandom or subject. Photography forums, football supporter groups, book clubs, gardening Facebook Groups. Membership is voluntary and driven by enthusiasm.
2. Communities of practice
Professionals sharing craft knowledge. Developer communities, teacher networks, community manager Slack groups. The value is peer learning and career progression.
3. Support communities
People navigating a shared circumstance. Chronic illness groups, new parent forums, bereavement spaces, recovery communities. Emotional safety and moderation quality matter more here than anywhere else.
4. Brand and customer communities
Hosted by a company for its users. Product forums, customer success communities, beta programmes. These reduce support load, surface product feedback and increase retention.
5. Learning communities
Cohort based courses, alumni networks, study groups. The community is the delivery mechanism for education rather than an add on.
6. Communities of place
Digital spaces anchored to a physical location. Neighbourhood groups, local buy and sell pages, city subreddits.
7. Communities of action
Organised around a shared goal. Campaign groups, mutual aid networks, open source projects, fundraising communities.
Where online communities live
The platform shapes the culture, so the choice is not neutral.
- Forums and dedicated platforms (Discourse, Circle, Bettermode, Hivebrite). Best for searchable knowledge, long form discussion and content you own.
- Chat platforms (Discord, Slack). Best for real time energy and social bonding. Weak for archiving knowledge. According to Backlinko's compilation of Discord data, Discord has more than 200 million monthly active users based on company figures, with around 19 million servers active each week.
- Social platform groups (Facebook Groups, LinkedIn Groups, WhatsApp communities). Best for low friction growth. You are renting the relationship.
- Reddit. The largest general purpose home for online communities. Reddit's own Q1 2025 earnings release describes the platform as having more than 100,000 active communities and over 108 million daily active unique visitors, a figure that has continued climbing since.
- Email and newsletter communities. Underrated. High deliverability, low interactivity unless paired with something else.
Why online communities matter
For people
The social case has become a public health case. The WHO Commission on Social Connection reported in June 2025 that one in six people worldwide is affected by loneliness, and that loneliness is linked to an estimated 871,000 deaths every year, roughly 100 deaths an hour. The WHO's summary of the Commission's findings notes that rates are highest among adolescents and young adults, at around one in five.
Online communities are not a substitute for in person connection, and the evidence on digital connection is mixed. But for people who are geographically isolated, housebound, neurodivergent, working unsociable hours, or living with a rare condition, a well moderated online community is often the most accessible source of people who understand their situation.
For organisations
Community has moved from a nice to have to a measurable line item. Hivebrite and Wonderly's Community Growth and Benchmark Report 2026, based on a survey of 186 marketers, community managers and C suite leaders, found that 76.9 percent of respondents named events, online or in person, as the single biggest driver of meaningful participation, followed by peer to peer support at 40.8 percent and discussion forums at 37.4 percent.
The same report identified a measurement gap worth noting: 53.7 percent do not compare metrics between members and non members, and 19 percent do not consistently track metrics at all, even though 77.6 percent say they are confident explaining community's value to senior leadership.
The commercial benefits organisations typically pursue:
- Lower support costs through peer to peer answers and searchable archives
- Higher retention, because switching away means leaving people behind
- Product insight that surveys cannot surface
- Advocacy, since community members are the people most likely to recommend you
- Owned distribution that no algorithm change can take away
Common challenges
Anyone considering starting an online community should plan for these from day one.
The empty room problem. New communities fail most often in the first 90 days, when there is nothing to react to. Seed conversations deliberately and invite a founding cohort before opening the doors.
Moderation load. Moderation is a real job with a real cost, and volunteer moderator burnout is a well documented failure mode across the sector.
Harassment and safety. Online spaces reproduce and sometimes amplify offline hostility. Clear rules, fast enforcement, easy reporting and consequences that actually bite are the baseline.
Platform dependency. If your community lives entirely inside someone else's product, a policy change or price rise can remove it overnight. Keep an email list.
Measuring the wrong thing. Member count is a vanity metric. Track active contributors, retention by cohort, questions answered and time to first response.
How to build an online community: the short version
- Define the purpose. One sentence, written from the member's point of view.
- Pick your first 50 members deliberately. Invite people who already know each other or share a strong common thread.
- Choose the platform to fit the behaviour, not the other way round. Real time chat for energy, forums for knowledge.
- Write the guidelines before you launch. Norms are far easier to set than to reset.
- Create a reason to return. A weekly ritual beats a permanently open door.
- Recognise contributors early and publicly. The first ten people who post set the tone for the next thousand.
- Measure participation, not headcount. Growth follows engagement, not the reverse.
Most online communities take a year or more to reach self sustaining engagement. Plan the resourcing accordingly.
FAQs
What is an online community in simple terms?
An online community is a group of people who meet in a digital space because they share an interest, goal or situation, and who talk to each other over time. The defining feature is member to member interaction, not one way content.
What is the difference between an online community and social media?
Social media is built around reach and follower relationships between a creator and an audience. Online communities are built around reciprocal relationships between members, with shared norms, defined membership and persistent conversation.
What are examples of online communities?
Subreddits, Discord servers, Facebook Groups, Slack workspaces for professionals, product support forums, fandom communities, cohort based course groups, open source project communities and neighbourhood groups.
How many people are in online communities?
There is no single reliable global figure, because definitions vary widely. As context, Reddit alone reports more than 100,000 active communities, and internet access now reaches 6.12 billion people according to DataReportal.
Do online communities need to be private?
No. Public, private and hybrid models all work. Private communities usually see higher trust and candour. Public ones gain search visibility and easier discovery.
How many members do you need to start an online community?
Fewer than most people assume. A group of 30 to 50 engaged people generates more valuable conversation than 5,000 passive sign ups.
Are online communities good for mental health?
The evidence is mixed and depends heavily on moderation quality and the nature of the space. Supportive, well moderated communities can reduce isolation, which the WHO identifies as a significant health risk. Poorly moderated spaces can do the opposite. If you are struggling, an online community is best used alongside professional support rather than in place of it.
Sources
- DataReportal, Digital Around the World, 2026
- Nielsen Norman Group, Participation Inequality: The 90-9-1 Rule
- WHO, Social connection linked to improved health and reduced risk of early death, 30 June 2025
- WHO Commission on Social Connection
- Reddit, Inc. Q1 2025 Earnings Press Release
- Backlinko, Discord User and Funding Statistics
- Hivebrite and Wonderly, Community Growth and Benchmark Report 2026
- McMillan, D. W. and Chavis, D. M. (1986), Sense of Community: A Definition and Theory
