The verdict
On the data we hold, it's close: neither pulls ahead on features, a free plan or AI access. The choice comes down to how you work.
What the data says
- Both cover 2 of the 2 features we compared.
- Both have a free plan, so you can try each before you pay.
- Both have an API and an MCP server, so either works with AI employees.
- In our HR ranking, Confluence places 1 and Slack 3 of 27.
Side by side
| 6 points compared | ||
|---|---|---|
| Starts at | $5.42/mo | €8.25/mo |
| Free plan | Yes | Yes |
| API | Yes | Yes |
| MCP server | Yes | Yes |
| AI summary + action items | Yes | Yes |
| Guest / external access | Yes | Yes |
| Links |
Plans and pricing
Confluence
- FreeFree forever for up to 10 users.Free
- StandardPer user per month; price shown in the page's structured data for 1 to 300 users.$5.42/mo/seat
- PremiumPer user per month; connects work across teams; price for 1 to 300 users.$10.44/mo/seat
Slack
- FreeFree forever: 90 days of message history, up to ten apps, 1:1 meetings.Free
- ProEUR 8.25 per user per month when paying monthly; unlimited history and apps; 50% off for the first three months.€8.25/mo/seat
- Business+EUR 18 per user per month when paying monthly; advanced AI and SAML single sign-on; 50% off for the first three months.€18/mo/seat
Prices as the vendors list them. They change often; the final price is on their sites.
Who each is for
Choose Confluence if…
Product, engineering, marketing and operations teams that already use Jira and want specs, documentation and shared knowledge in a wiki that sits next to their issue tracker.
Choose Slack if…
Teams of any size that need real-time messaging, channels and quick decisions in one place, and want chat connected to their CRM, project tools and alerts.
Other options worth a look
ToolBring teams together on an infinite whiteboard to brainstorm, diagram and run workshops in real time.HR
From $8/mo yearlyFree plan
ToolWrite and edit documents collaboratively in the browser with instant sharing and version history.HR
From €6.80/moFree plan
ToolAutomatically transcribe and summarise meetings across Zoom, Google Meet and Teams with searchable AI chat.HR
From $8.33/mo yearlyFree plan
ToolCentralises standard operating procedures, quizzes and onboarding materials in a searchable knowledge base.HR
From $3/mo yearlyAffiliate link- ToolThe Bloom Growth Operating System: scorecard, meetings, goals and issues on one platform, the software half of the EOS/Traction category.
HR
From $299/mo
ToolAI assistant built into Zoom that generates meeting summaries, action items and automated follow-up tasks.HR
From €15.33/mo yearlyFree plan