Slack vs Microsoft Teams: Price, Features and Which to Choose

Slack and Microsoft Teams both do the same basic job — group chat, channels, calls, and file sharing for a company — but they get there from opposite directions, and that shapes who should pick which. Slack is a standalone chat app with its own pricing ladder and an AI layer it sells in three named tiers; Microsoft Teams is the communication hub built into Microsoft 365, so most paid seats already include it at no extra line-item cost, while a cheaper $4-per-user standalone version exists for teams that don't use Microsoft's suite. If your company already runs on Microsoft 365, Teams is close to a default choice on price alone. If you're chat-first, want a generous free tier, or aren't tied to Microsoft's ecosystem, Slack's free and Pro tiers are built to feel like a product in their own right rather than an add-on.

Pricing and plans compared

Slack's official pricing page lists four tiers: Free, Pro, Business+, and Enterprise+. Pro lists at $8.75 per user per month billed monthly, dropping to $7.25 per user per month on annual billing; Business+ lists at $18 monthly or $15 per user per month annually; Enterprise+ is sold on annual contracts starting around $45 per user per month, with custom pricing for large deployments handled by Slack's sales team.

Microsoft's approach is split in two. Standalone Microsoft Teams Essentials — the plan aimed at small businesses and organizations that don't run the rest of Microsoft 365 — launched, according to Microsoft's own 2021 announcement, at $4 per user per month and includes meetings of up to 30 hours and up to 300 participants. For everyone else, Teams simply comes included with Microsoft 365 Business Basic, Business Standard, Business Premium, and the Enterprise E1/E3/E5 tiers, so there's no separate "Teams price" to compare — the cost is whatever the surrounding Microsoft 365 subscription costs.

Free plan limits: history, storage, and participants

This is where the two products diverge the most, and it's the single biggest reason "slack vs teams cost" is such a common search: the free tiers are free in name only once a team gets past a handful of people.

On Slack's free plan, per Slack's own usage-limits help page, workspaces can view and search only the most recent 90 days of messages and files — anything older is hidden, not deleted, until the one-year mark, at which point Slack's policy allows messages and files older than a year to be deleted on a rolling basis. Free workspaces are also capped at 10 installed third-party or custom apps, which matters if your team leans on Slack as an integration hub rather than just a chat tool.

Microsoft Teams' free, personal-use tier works differently because it isn't trying to be a business product at all. According to Microsoft's own support documentation, the free version gives each person 5 GB of storage for documents, PDFs, and other files shared in chats and communities — though photos and videos aren't counted against that cap and can be shared without limit. There's no stated message-history cutoff comparable to Slack's 90-day rule, but the free tier also isn't meant for a company-wide deployment the way Slack Free sometimes ends up being used.

Storage and file-sharing limits

Once you're on a paid or bundled plan, the comparison shifts from "how much do I get" to "how is it architected." Slack caps individual uploads at 1 GB per file, per its file-storage help article, which also notes that up to 10 files can be dragged and dropped into a conversation at once.

Microsoft Teams inherits SharePoint's storage architecture, since every team in Teams gets a backing SharePoint site and every channel gets a document library folder there. Microsoft's limits and specifications documentation states that Business Basic, Business Standard, and Office 365 Enterprise E1/E3/E5 plans each include 1 TB of SharePoint storage per organization plus 10 GB per licensed user, with individual team or group sites able to hold up to 25 TB and a per-file upload ceiling of 250 GB — far above Slack's 1 GB cap. Inside an actual chat message, though, Teams is tighter: attachments are capped at 100 MB each, with a maximum of 10 attachments per message, and each chat post is limited to roughly 100 KB of text, mentions, and reactions combined.

Core features: channels, chat, and calls

Functionally, both tools cover the same ground: persistent channels organized by team or topic, threaded and direct messaging, voice/video calls, and screen sharing. Slack's calling feature, Huddles, is built as a lightweight, always-available audio/video drop-in rather than a scheduled meeting; Microsoft Teams calling and meetings are the more full-featured side of the product, inherited from Skype for Business, with scheduled meetings, breakout rooms, live captions, and — per Microsoft's licensing documentation — support for up to 300 meeting participants on Business and Essentials plans, rising to 1,000 on higher Enterprise (E3/E5-class) licenses.

That calling depth is part of why Microsoft positions Teams against video-first tools as much as against Slack; Pandromeda's earlier look at Zoom, Teams, and Google Meet covers that video-conferencing side of Teams in more depth. This piece is specifically about the chat-and-collaboration layer, which is where Slack has traditionally had the edge in day-to-day usability — a cleaner search experience, a more mature app/integration model, and channel organization most people find more intuitive than Teams' nested team-and-channel structure.

AI features: Slack AI vs Microsoft Copilot

Both companies have layered generative AI on top of their core product, but they sell it in structurally different ways. Slack bundles its AI under three named tiers directly on its pricing page: Basic AI (available on Free and Pro), Advanced AI (Business+), and Enterprise-Grade AI (Enterprise+). The concrete features listed include Slackbot as a personal AI agent, AI-generated conversation and thread summaries, AI-assisted workflow generation inside Workflow Builder, AI-powered search, daily recap digests, file summaries, huddle notes, message translation, and AI writing assistance inside Slack canvases — with full Slackbot access and enterprise-grade search reserved for the Business+ and Enterprise+ tiers respectively.

Microsoft takes the opposite approach: rather than folding AI into Teams' base tiers, it sells Microsoft 365 Copilot as a separate, paid add-on that layers Copilot's meeting-recap, chat-drafting, and summarization features on top of a qualifying Microsoft 365 or Teams subscription. That means an organization's actual AI cost in Teams depends on which add-on SKU it buys, rather than being baked into a single advertised plan price the way Slack's AI tiers are — worth confirming directly with Microsoft or a partner before budgeting, since Copilot licensing has changed more than once in the past couple of years. It's also worth noting Microsoft reuses the "Copilot" name across very different products — the Microsoft 365 Copilot in Teams is a separate thing entirely from GitHub Copilot, which Pandromeda has covered separately on the developer-tooling side, so buyers should double-check which Copilot a sales conversation is actually about.

Integrations and the wider ecosystem

Slack's app ecosystem is built around its own app directory, with the free plan's 10-app cap lifted entirely on paid plans. Microsoft Teams' integration story runs through the Microsoft 365 ecosystem itself — native, often frictionless connections to Outlook calendars, SharePoint, OneDrive, Planner, and Office apps — plus its own Teams app store for third-party add-ins. If your company's software stack is already Microsoft-centric, that native integration is a real advantage Teams has that's hard for Slack to fully replicate, even with Slack Connect bridging external organizations. The flip side is true too: companies whose tools span Google Workspace, best-of-breed SaaS, and non-Microsoft infrastructure often find Slack's integration model more neutral. Pandromeda's comparison of Google Workspace and Microsoft 365 is a useful companion read if the chat app is really a proxy decision for which productivity suite to standardize on.

Security, admin controls, and compliance

Enterprise buyers care less about the chat UI and more about what IT can control. Both vendors gate their strongest admin, retention, and compliance features behind their top tiers — Slack's Enterprise+ and Microsoft's higher Microsoft 365 Enterprise licenses, respectively. Because Teams data lives in SharePoint and Exchange Online, it inherits Microsoft 365's existing compliance tooling (eDiscovery, retention policies, Purview) automatically for organizations already using those services — a meaningful advantage for regulated industries that have already built compliance workflows around Microsoft 365. Slack's equivalent controls — data loss prevention, legal holds, and custom retention — are concentrated in its Enterprise+ tier and typically require separate configuration from any Microsoft 365 compliance stack a company might already run in parallel.

Who should choose Slack

Slack tends to make the most sense for companies that are chat-first and not deeply tied to Microsoft's productivity suite: startups, agencies, and distributed teams that value a clean search experience, a large third-party app catalog once you're past the free tier, and a lighter, channel-centric way of organizing conversations. It's also the stronger pick if you need to collaborate with lots of outside organizations, since Slack Connect was built specifically for cross-company channels.

Who should choose Microsoft Teams

Teams is the more obvious choice for organizations already paying for Microsoft 365 Business or Enterprise licenses, since in that scenario Teams effectively costs nothing extra and comes pre-wired into Outlook, SharePoint, and Office files. It also wins outright on meeting capacity and calling depth — the 300-to-1,000-person meeting ceilings and built-in webinar/town-hall tooling go well beyond what Slack Huddles are designed to do. For a small business not on Microsoft 365 at all, Teams Essentials at its original $4-per-user-month pricing undercuts Slack Pro, albeit with a lighter feature set than the full Microsoft 365 bundle.

Bottom line: what to check before you decide

Neither product is free once a team scales past casual use, and the honest comparison isn't "Slack vs Teams" in isolation so much as "Slack vs whatever your Microsoft 365 subscription already includes." Before committing, check three things directly with each vendor: your organization's current Microsoft 365 tier (since Teams may already be fully paid for), Slack's current message-history and app-limit thresholds on whichever plan you're evaluating, and current Copilot or Slack AI add-on pricing, since both companies have adjusted their AI packaging more than once in the past two years. For most Microsoft-standardized companies, Teams is the default; for everyone else, Slack's Pro tier remains the more self-contained, chat-first product to evaluate against it.

Written byFelix Moreau

Felix Moreau writes Pandromeda's software coverage and how-to guides. He covers Windows, macOS and Linux updates, the apps people rely on, emulators and developer tools, and turns official documentation into clear, numbered steps that work on the current version.

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