Slack vs Teams (2026): Which Fits Your Team? | Siit

Dimitri Cabete Jorge, IT & Security Editor · Last updated: August 2026 · Facts verified: August 2026

TL;DR: Choose Microsoft Teams if you already pay for Microsoft 365, where meetings and Office co-authoring are included in existing licensing, and where webinars and town halls run at sizes Slack has no equivalent for. Choose Slack if chat is the center of your work: threading and search are stronger than Teams', and Slack has the larger documented app directory. Your existing stack decides the answer more than any feature checklist.

Ratings: Slack: G2 4.5/5 · Microsoft Teams: G2 4.4/5, verified August 2026

Slack vs Microsoft Teams at a Glance

Existing Microsoft 365 licensing is the primary decision factor. After licensing, compare chat workflow with meeting capacity and AI packaging.

Overview of Slack

Slack is a channel-based messaging platform owned by Salesforce, built around persistent channels and mature threading, with one of the largest third-party app directories in team chat. Its 2026 AI lineup includes conversation summaries, AI search answers, and Slackbot, a personal AI agent. Slack Connect lets workspaces share channels directly with outside organizations. Teams that need large scheduled meetings, or that already pay for Microsoft 365, are the buyers most likely to look elsewhere.

Key features:

• Threads: Replies live in a side panel and can be posted back to the channel, so busy channels stay readable.
• Huddles: Spontaneous audio and video calls, closer to a desk drop-by than a scheduled meeting.
• Workflow Builder: No-code automation with 65 third-party connectors, which keeps routine approvals and intake forms moving without a developer.
• AI in Slack: Summaries, huddle notes, translations, and enterprise search; catching up on a channel you were away from takes a click instead of a scroll.
• Search: Modifier-based filters (from:, in:, has:) plus semantic AI search across the workspace, so old decisions stay findable without asking the original poster.

Ideal for: chat-first companies on a SaaS stack, especially engineering-heavy teams and companies using Salesforce.

Overview of Microsoft Teams

Microsoft Teams is Microsoft's collaboration hub for chat, meetings, calling, and file work, bundled with most Microsoft 365 plans. Its strength is depth inside the Microsoft stack: Outlook scheduling, SharePoint storage, and co-authoring Word, Excel, and PowerPoint files without leaving the app. Threaded channel conversations now exist. This closes a long-standing gap with Slack. Chat-heavy teams outside Microsoft 365, or anyone sensitive to a heavy desktop client, may want an alternative.

Key features:

• Large meetings: Scheduled meetings with breakout rooms, recording, and view-only overflow for larger audiences, which covers training sessions and all-hands that Huddles cannot host.
• Large events: Webinars and town halls for larger audiences, with add-ons raising the caps further.
• Office integration: Co-edit documents in-app; files land in SharePoint and OneDrive automatically.
• Copilot: AI meeting recaps, chat summaries, and drafting, available as a paid add-on; recaps replace a dedicated note-taker.
• Governance: Purview retention policies and eDiscovery (legal search and export of chat records) across chats and channels.

Ideal for: Microsoft 365 organizations that run structured, meeting-heavy work.

Side-by-Side Feature Comparison

Slack and Microsoft Teams differ most in chat workflow and meeting capacity. AI packaging and compliance controls also matter; everyday chat is close to parity.

Pricing

Slack bills per user for messaging alone; Teams pricing is really Microsoft 365 pricing, with a standalone option since Microsoft unbundled the suites.

Slack:

• Free: $0; 90 days of searchable history, 10 app integrations, 1:1 Huddles only.
• Pro: $7.25/user/month billed annually ($8.75 monthly); full searchable message history, group Huddles, conversation summaries, and huddle notes.
• Business+: $15.00/user/month billed annually ($18.00 monthly); Security Assertion Markup Language (SAML) single sign-on, data exports, AI search answers, recaps, and Slackbot.
• Enterprise+: Custom pricing; HIPAA support, DLP, legal holds, audit logs, and enterprise search.

Microsoft Teams:

• Microsoft Teams Free: $0; no published free-tier history limit, with retention set by admin policy.
• Microsoft Teams Essentials: $4.00/user/month billed annually; 300-participant meetings with recording.
• Microsoft 365 Business Basic: $7.00/user/month billed annually; Teams plus Exchange, SharePoint, and 1 TB of OneDrive.
• Microsoft 365 Business Standard with Copilot: $23.50/user/month billed annually; the Copilot-bundled Business Standard tier.
• Teams Enterprise (standalone): $8.55/user/month billed annually.
• Microsoft 365 Copilot add-on: $30.00/user/month billed annually on enterprise plans; $21.00/user/month for small and midsize businesses (SMBs), with a promotional $18.00 rate for up to 300 users.

Rates come from Slack's pricing page and Microsoft's Teams plans page. All pricing information verified August 2026.

Gotchas:

• Slack: Free workspaces delete data older than one year outright.
• Slack: The 50%-off-for-three-months promo covers only monthly Pro and Business+ plans bought within 7 days of team creation, not annual billing.
• Slack: Enterprise+ replaced Enterprise Grid, which cannot be purchased after the next renewal following March 1, 2027.
• Teams: Microsoft's July 1, 2026 licensing update prices Business Standard without Copilot at $14.00/user/month; $23.50 is the Copilot bundle.
• Teams: Intelligent recap and other advanced meeting AI need Teams Premium ($10.00/user/month) or a Copilot license; audio recap requires Copilot.

For most SMBs, the practical comparison is Slack Business+ against Microsoft 365 Business Basic plus whichever AI add-on the team will use.

What Users Say

Scores sit close together on every platform. Reviewers praise Slack's chat interface and threading, while Teams earns praise for Microsoft 365 depth and meeting quality. Slack complaints focus on cost; Teams complaints focus on the client.

• Slack is rated 4.5/5 on G2, 4.6/5 on Gartner Peer Insights, and 4.7/5 on Capterra; reviewers credit search with acting as a persistent team memory.
• On G2 and Capterra, the most common Slack complaint is notification overload and message burial in large workspaces.
• On Reddit and Hacker News, Slack criticism centers on seat economics and contract rigidity: one 200-user company reported a five-figure annual increase to unlock single sign-on (SSO), and the top-voted reply recommended Teams as the workaround. Several threads describe annual contracts that could not be reduced when headcount fell.
• Microsoft Teams is rated 4.4/5 on both G2 and Gartner Peer Insights and 4.5/5 on Capterra.
• Teams' dominant practitioner complaint is client weight and reliability: heavy RAM and CPU use, New Teams regressions such as missed calls and failed notifications, and reports of Teams idling at roughly three times Slack's memory footprint.

User sentiment sourced from G2, Capterra, Gartner Peer Insights, Reddit, and Hacker News as of August 2026.

That split maps onto the purchase decision. A company that can absorb Slack's per-seat cost gets the better-reviewed chat tool, while a company standardized on Microsoft 365 gets a workable one it already pays for, plus meeting features Slack does not attempt.

When to Choose Slack vs Microsoft Teams

Your existing software and meeting requirements determine the better choice.

Choose Slack if you need:

• A chat-first workspace with established channel conventions
• Deep integrations with a SaaS stack (Salesforce, Jira, GitHub, Linear)
• External-partner channels through Slack Connect
• AI for chat-heavy work without a separate add-on
• Keyword-level notification alerts

Choose Microsoft Teams if you value:

• Minimal added cost on an existing Microsoft 365 subscription
• Meetings and large events beyond Huddles' capacity
• Co-authoring Office documents without leaving the chat or meeting
• Governance through existing Microsoft licensing

Review your Microsoft 365 licenses before comparing feature lists because existing costs may determine the lower-cost choice.

How Slack and Microsoft Teams Work with Siit

Slack and Microsoft Teams are both native Siit integrations, so employees hold whole conversations with Siit inside the chat app they already use. Siit is an AI Service Desk for IT and HR requests. Employees raise requests by mentioning @Siit in a public channel, sending it a DM, or right-clicking a message in a private channel or DM; admins can turn any message into a ticket. Siit answers with context pulled from 500+ connectable apps. It syncs device, identity, and human resources information system (HRIS) data into the request.

Siit works with either platform; see Siit's integrations for how a request moves from a channel message to resolution.