Discourse vs Slack Comparison 2026
Discourse is a public, searchable forum: free to host, indexed by Google, with no per-seat charge at any size. Slack organises a community into channels and threads instead, free for ninety days of message history and ten app connections, then $8.75 a user a month for Pro. Slack charges by the seat, so a hundred-member community runs close to $875 a month there against a flat fee on Discourse. The choice is a public archive that scales for free, or a private, searchable room that scales with headcount.
Forum software, hosted or run yourself
Channels for a community that outgrew a group chat
At a glance
- Slack starts cheaper, at $8.75.
- Both have a genuinely free tier.
Side by side
Discourse | Slack | |
|---|---|---|
| Starting price (they differ) | From $100 | From $8.75 |
| Pricing model | Free plan, paid tiers | Free plan, paid tiers |
| Free tier | Yes | Yes |
| Billing | Monthly or annual | Monthly or annual |
| Free trial | Not stated | Not stated |
| API | Yes |
Discourse
Forum software, hosted or run yourself
Discourse is the forum the internet settled on: threaded, searchable, indexed by Google, and open source, so a community that outgrows the hosted plans can take the database and run it on its own server. That escape hatch is the argument for it over anything closed. The hosted pricing starts where a hobby project stops, and self-hosting swaps the bill for a sysadmin.
Our note
The reason to choose this over Circle or Mighty Networks is that the conversation is public and indexed, which makes the forum an asset rather than a cost. The reason not to is that it is a forum, and an audience raised on Discord will find it slow.
Only on this side
- Covers website builders
Slack
Channels for a community that outgrew a group chat
Slack organises a community into channels, threads and searchable history, which is what a paid membership community usually needs once a Discord server stops being enough. The free plan keeps ninety days of messages and ten app connections, and that history limit is what pushes most groups onto a paid plan rather than any feature. Guests from outside the workspace can be given a single channel. Paying by seat means a large free community costs more here than on software priced per workspace.
Why people weigh these two
- Slack instead of Discourse
- Slack is the chat-channel route for a community that outgrew a group chat, free to start, the pick when live conversation matters more than a searchable archive.
- Discourse instead of Slack
- Discourse keeps every post searchable forever with no history limit, and can be self-hosted, with a free tier before a $100 plan, where Slack's free plan drops messages after ninety days.
Which one should you pick
Buy Discourse if the community is large, mostly free to join, and the conversation should be findable by search a year later. A real free hosted plan exists, Pro tops out at $100 a month regardless of how many people show up, and self-hosting is free apart from a server.
Buy Slack if the group is smaller, already paying for something else, and expects a professional room rather than a public forum. Pro is $8.75 a user a month and removes the ninety-day history cap that is the free plan's real limit. Per-seat pricing punishes a large free community here: count the seats before assuming Slack is the cheaper choice.
Common questions
- Which is cheaper for a large community?
- Discourse, by a wide margin, if most members are not paying you. Its plans are flat regardless of headcount, topping out at $100 a month for Pro. Slack charges per seat, so a hundred-member community runs close to $875 a month on its Pro plan.
- What is the real limit on Slack's free plan?
- Message history: only the last ninety days are kept, and ten app connections are allowed. That history cap, more than any missing feature, is what pushes most paid upgrades to Pro at $8.75 a user a month.
- Is Discourse's content public and searchable?
- Yes, threads are public pages indexed by search engines, which turns a forum into a source of traffic over time. Slack's channels are private to the workspace by default, built for a team or paid community rather than a public archive.
- Which is better for a small, paying team?
- Slack, if members are already living in it and the group is small enough that per-seat pricing stays reasonable. Discourse is built more for scale and public archiving than for the kind of quick, threaded back-and-forth a small paid team expects from chat.
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