Slack Pricing Explained: What 90-Day History Actually Costs You

Every Tier at a Glance

Slack uses per-user pricing on all paid tiers. Every active member of your workspace counts as a user. Guests (people invited to specific channels from outside your org) also count toward user limits on Free but can be added at reduced cost on paid tiers.

The 90-Day History Problem

Slack Free hides messages older than 90 days. They're not deleted — they're inaccessible. If you upgrade later, they come back. But while you're on Free, here's what this actually costs:

• Lost decisions. A pricing decision made in January is invisible by April. Someone asks "why did we choose X?" and nobody can find the conversation.
• Lost links and references. That useful article someone shared? That API documentation link? Gone after 90 days.
• Lost onboarding context. New hires can't read historical discussions to understand how the team works. They have to ask questions that were already answered.
• Lost accountability. Who agreed to what? When was it decided? Without message history, there's no record.

The 10-Integration Limit

Slack Free limits you to 10 app integrations. That sounds like enough until you count: Google Drive (1), Zoom (2), GitHub (3), Jira (4), Google Calendar (5), Notion (6), Figma (7), HubSpot (8), Zapier (9), Loom (10). You're at the limit with a basic tech stack.

On Slack Pro, integrations are unlimited. The 2,600+ app marketplace opens fully, and the integration limit stops being a constraint.

What Each Tier Adds

Free — Functional but Fragile

Channels, direct messages, 1:1 voice/video calls, threads, and basic file sharing at $0. For a team of 2–5 people working closely who don't need long-term message history or many integrations, Free works.

Pro ($8.75/user/mo) — The Standard

Pro removes the 90-day limit (unlimited message history), unlocks all integrations, adds group video calls (up to 50), Slack Huddles, guest access for external collaborators, Slack AI summaries, and 10GB storage per user.

Why most teams end up here: Unlimited history and unlimited integrations are table stakes for any team that relies on Slack as their communication hub. Pro is the real starting tier for business use.

Business+ ($18/user/mo) — Compliance and SSO

Business+ adds SAML SSO, advanced Slack AI features, compliance message exports, data loss prevention tools, and a 99.99% uptime SLA. The jump from $8.75 to $18 is primarily driven by SSO and compliance needs.

When it's worth it:If your IT team requires SAML SSO for all tools, or if you need compliance exports for regulatory purposes. Most teams under 50 people don't need Business+.

Enterprise Grid (Custom) — Multi-Workspace Organizations

Enterprise Grid adds unlimited connected workspaces, enterprise key management (EKM), DLP with third-party tools, eDiscovery, HIPAA compliance, FedRAMP (GovSlack), and a dedicated customer success manager. For large organizations with multiple departments needing separate workspaces that interconnect.

Hidden Costs

• Per-user pricing scales linearly. Every active user costs the full per-user rate. A 50-person team on Pro pays $437.50/month ($5,250/year). There are no volume discounts until Enterprise Grid.
• Slack AI is included in Pro and above but the AI features have usage considerations. Heavy AI summarization of long threads may consume more than expected.
• Guest access costs on paid tiers. External guests on Pro and Business+ may be billed as full users or at reduced rates depending on their access level. Single-channel guests are typically free; multi-channel guests count as paid users.
• No built-in project management. Slack is communication, not task management. You'll need a separate PM tool (Asana, ClickUp, Linear), adding to your total stack cost.
• Notification overload at scale. Large Slack workspaces (100+ people, 50+ channels) create significant notification management overhead. This is a productivity cost, not a dollar cost, but it's real.

Which Tier Do You Need?

Per-User Math at Team Scale

Cheaper Alternative

Discordis free with unlimited message history, unlimited integrations, unlimited voice/video channels, and no user cap. For startups, communities, and teams that don't need enterprise compliance, Discord gives you more for $0 than Slack Free. The tradeoffs: no SAML SSO, no compliance exports, fewer business-specific integrations, and a less professional perception.

Microsoft Teamsis included with Microsoft 365 Business Basic ($6/user/month). If your team already pays for Microsoft 365, Teams is effectively free and includes unlimited chat history, video meetings, and file storage. The tradeoff: Teams' third-party app ecosystem is smaller than Slack's, and many developers and startups find its UX less intuitive.