Slack review: still the best team chat, but the free plan forgets fast

Slack is a team messaging app owned by Salesforce. Work happens in channels, organised by project, team or client, with threaded replies, direct messages, audio and video huddles, shared documents called canvases, and automated workflows. Salesforce bought Slack in 2021, and since June 2025 every paid plan has included AI features instead of a separate AI add-on.

On the Cybernock research rubric Slack scores 8.7/10, first in our best team chat apps list. Integrations and day-to-day polish carry it. Price drags it down, and so does a free plan that hides everything older than 90 days.

How does Slack work for a small or mid-sized business?

Conversation is organised by channel rather than by person. When you hire someone, they can read a project’s history instead of being forwarded old emails. Paid plans keep that history forever; the free plan shows only the last 90 days.

A typical 20-person company runs a few dozen channels: one per team, one per client or project, and a handful for announcements and social chat. Replies go into threads so the main channel stays readable; in practice, teams that skip threads end up with noisy channels fast. Huddles start a quick voice or video call inside a channel without a calendar invite, and on paid plans they hold up to 50 people, with up to 25 cameras on at once and two people sharing screens (Slack help, huddles). Each huddle gets its own canvas and thread for notes.

Which Slack features matter most?

• Integrations and bots: Slack’s app directory is the largest in team chat, and its developer platform is the most widely supported. GitHub, Jira, Google Drive, Salesforce and most help-desk tools post straight into channels.
• Slack Connect: a channel shared with another company’s Slack workspace. Paid plans can invite whole partner teams; the free plan is limited to 1:1 external DMs.
• Guests: single-channel guests are free, up to 5 for every paid member, which suits agencies and contractors (Slack guest accounts).
• Workflow Builder: no-code automations for requests, approvals and onboarding checklists.
• AI: conversation summaries on every plan, huddle notes on Pro, and AI search, daily recaps, translation and AI-generated workflows on Business+. Agentforce agents and some partner AI apps are billed separately.

How much does Slack cost?

Pro costs $7.25 per user a month on annual billing or $8.75 month to month. Business+ costs $15 annually or $18 monthly. Enterprise+ now has a public list price of $45 per user a month on annual billing, though large buyers negotiate it down.

These are US list prices from Slack’s pricing page in October 2026. The June 2025 restructure raised Business+ from $12.50 to $15 on annual billing while adding AI that used to cost extra, and left Pro unchanged (Slack announcement). Vendr’s purchase data puts the median negotiated Enterprise price at about $26 per user, well below the $45 list price.

For most businesses of 10 to 100 people, Pro on annual billing is the sensible default. Don’t pay for Business+ just for the AI recaps. Move to Business+ when you need SAML single sign-on, exports that include private channels and DMs, or data stored in a specific region. A 25-person team pays $2,175 a year on Pro or $4,500 on Business+.

Is Slack’s free plan still worth using?

Only for a trial, or for small groups that treat chat as disposable. Most people miss the second limit: beyond hiding anything older than 90 days, Slack has since 26 August 2024 deleted free-plan data older than one year (Slack free plan limits).

The free plan also caps you at 10 apps, 1:1 huddles and 1:1 Slack Connect. By contrast, Pumble keeps unlimited history for unlimited users on its free plan, and Chanty does the same for teams of up to five.

How secure is Slack, and can you keep control of your data?

Slack holds SOC 2 Type II and ISO 27001, 27017, 27018 and 42001 certifications, offers FedRAMP Moderate on Enterprise plans, and runs a separate GovSlack with FedRAMP High (Slack compliance). HIPAA support is listed only on Enterprise+. Enterprise Key Management, which lets you hold the encryption keys in AWS, is an add-on for Enterprise plans.

There is no end-to-end encryption and no self-hosted version, so Slack can technically read workspace content. Exports are split by plan: Free and Pro can export public channels only, while Business+ and Enterprise can export private channels and DMs after Slack approves the request.

Salesforce has also tightened access to Slack data. In May 2025 it cut the rate limit on message-history API calls to one request a minute for commercial apps that are not in the Slack Marketplace, and later in 2025 it changed its API terms to bar bulk export of Slack data and its use for training large language models (Hunton, August 2025). If you plan to feed Slack history into another AI search tool, don’t skip this check: confirm the tool is an approved Marketplace app.

Where does Slack fall short?

• The price gap: a 25-person team pays $2,175 a year on Slack Pro against $747 on Pumble Pro, both on annual billing.
• The free plan’s 90-day window and one-year deletion make it a trial, not a long-term option.
• No self-hosting and no end-to-end encryption, which rules Slack out for some defence, legal and health work.
• A February 2025 outage degraded service for about ten hours, a reminder that a single cloud vendor is a single point of failure.

Who should not buy Slack?

Skip the subscription if your company already licenses Microsoft 365 with Teams; you’d be paying twice for chat. Budget-first teams lose little by choosing Pumble, whose free tier keeps full history. Legal, defence and health teams that must self-host or need end-to-end encryption can’t get either from Slack, so Mattermost, Rocket.Chat or Element fit better. And when your team mostly writes long asynchronous updates across time zones, Zulip’s topic threads keep discussions easier to follow.

How does Slack compare with Teams, Google Chat and Pumble?

Microsoft Teams is nearly as good on our rubric and much better value when you already pay for Microsoft 365. Google Workspace includes Google Chat in every plan, which is enough for teams that mostly need quick messages beside Gmail and Docs. Pumble copies Slack’s layout at about a third of the price, with fewer integrations. Zulip is the better choice for teams that work asynchronously, thanks to its topic-based threads.

Should you buy Slack?

For most businesses not tied to Microsoft 365, yes. The evidence: it pairs the deepest integrations and the best external collaboration with the most polished apps. Start free for a week. Then move to Pro on annual billing before the 90-day window starts to bite.

The answer flips in three cases. If you’ve already paid for Microsoft 365 Business, use Teams and spend the money elsewhere. If price decides, Pumble gives you unlimited history for free. If you must host chat on your own servers, look at Mattermost or Rocket.Chat. See the full team chat ranking or browse all team chat reviews.