Slack

Slack is a channel-based workplace communication platform with messaging, huddles, file sharing, workflow automation, AI tools and third-party integrations.

8.6/10 TechZella Score
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At a glance

Quick Verdict

Slack offers mature messaging, huddles, canvases, workflow automation, AI features, extensive integrations and developer APIs. G2 reports a 4.5 out of 5 rating across more than 38,000 reviews. Free-plan retention and app limits reduce value for larger or archive-dependent teams.

Overview

Slack is a cloud-based workplace collaboration platform organized around public channels, private channels, direct messages and group conversations. It supports text communication, file sharing, search, audio and video huddles, screen sharing, canvases, lists and workflow automation.

Slack began as an internal tool and launched publicly in 2013. Salesforce completed its acquisition of Slack on July 21, 2021. Slack continues operating under its own brand within Salesforce.

The platform connects with more than 2,600 apps, including Salesforce, Jira, Asana, Google Drive, Dropbox, GitHub, Zendesk and Zoom. Developers can build custom apps using Slack’s APIs, OAuth authentication, webhooks, SDKs and workflow tools.

Key Features

Slack uses channels to organize conversations by project, department, customer or topic. Members can also communicate through direct messages and Slack Connect conversations with external organizations.

Huddles provide audio and video meetings, screen sharing, messaging and shared context inside channels or direct messages. Free workspaces limit huddles to two people and 30 minutes, while paid plans support group huddles.

Canvases provide collaborative pages for text, files, media, link previews and embedded workflows. Lists support structured task and project tracking on eligible paid plans.

Workflow Builder enables no-code automations. Slack’s API platform includes Web API methods, Events API subscriptions, Conversations API functions, incoming webhooks, Socket Mode, Admin APIs, SCIM APIs and Audit Logs APIs.

Slack AI can provide conversation summaries, search answers, daily recaps, file summaries and AI-generated workflow assistance. Availability depends on the workspace plan and administrator settings.

Pricing

Slack provides a permanent Free plan and paid Pro, Business+ and Enterprise+ plans. Prices vary by billing schedule and may change, so buyers should confirm totals on Slack’s pricing page.

The Free plan costs $0 and includes 90 days of searchable message and file access, limited app installations and one-to-one huddles. Content older than one year may be permanently deleted under free-plan retention rules.

Pro costs $8.75 per active user monthly when billed monthly, or $7.25 per user monthly when billed annually. It adds unlimited message history, unlimited app integrations, group meetings and expanded Slack Connect features.

Business+ costs $18 per user monthly when billed monthly, or $15 per user monthly when billed annually. It adds advanced AI capabilities and expanded administration features.

Enterprise+ uses custom pricing. Slack offers free trials for Pro and Business+ in eligible workspaces. Trial requests do not require a credit card, and workspaces revert to the Free plan without an upgrade.

Pros & Cons

Slack’s strengths include a mature channel structure, broad integration ecosystem, searchable conversations, flexible APIs and strong support for distributed teams. Its huddles and workflow tools reduce the need to switch between communication and work applications.

The main limitations are the Free plan’s 90-day visibility limit, possible deletion of content older than one year, app-installation restrictions and feature differences between plans. Large workspaces may also need governance to manage notifications, channel growth, permissions and data retention.

Alternatives

Microsoft Teams is a close alternative for organizations centered on Microsoft 365, Exchange, SharePoint and Azure. Google Chat suits teams already standardized on Google Workspace. Mattermost offers team messaging with self-hosting options. Zoom Workplace combines messaging, meetings and phone services. Discord can suit informal communities and developer groups, but it is less focused on enterprise administration.

FAQ

Does Slack have a free plan?
Yes. The Free plan costs $0 and includes channels, direct messages, file sharing, limited huddles and 90 days of searchable message and file access.

Does Slack offer a free trial?
Slack offers free trials for Pro and Business+ to eligible workspaces. Owners or administrators can request a trial, and no credit card is required to start it.

What platforms support Slack?
Slack supports web browsers and desktop applications for Windows, macOS and Linux. Mobile applications support Android and iOS, and Slack also supports iPad access.

What integrations does Slack support?
Slack lists more than 2,600 apps, including Salesforce, Jira, Asana, Google Drive, Dropbox, GitHub, Zendesk and Zoom. Third-party services may require separate subscriptions.

Does Slack have an API?
Yes. Slack provides Web, Events, Conversations, Admin, SCIM, Audit Logs and Status APIs, along with OAuth, webhooks, Socket Mode and official SDKs.

Is Slack suitable for external collaboration?
Yes. Slack Connect supports communication with external organizations through direct messages, group conversations and shared channels. Limits depend on the subscription plan.

Capabilities

Features

Communication

  • Public and private channels
  • Direct messages and group conversations
  • Slack Connect for external collaboration
  • Threads, reactions, mentions and notifications
  • File sharing and searchable conversations

Meetings

  • Audio and video huddles
  • Screen sharing
  • Huddle messaging
  • AI huddle notes on supported plans
  • Desktop, mobile and iPad huddle access

Work Management

  • Collaborative canvases
  • Lists for structured work tracking
  • Workflow Builder
  • Templates
  • App-based actions and notifications

AI

  • Conversation summaries
  • AI search
  • Daily recaps
  • File summaries
  • Slackbot personal AI agent
  • AI workflow generation
  • AI meeting notes

Integrations

  • 2,600+ apps in the Slack Marketplace
  • Salesforce, Jira, Asana and Google Drive integrations
  • Dropbox, GitHub, Zendesk and Zoom integrations
  • Workflow Builder connectors
  • Custom apps and agents

Developer Platform

  • Web API
  • Events API
  • Conversations API
  • Admin and SCIM APIs
  • Audit Logs API
  • Incoming webhooks
  • OAuth 2.0
  • Socket Mode
  • Official Python, JavaScript and Java SDKs
Product details

Specifications

DeploymentCloud-based SaaS
PlatformsWeb, Windows, macOS, Linux, Android, iOS and iPadOS
APIWeb, Events, Conversations, Admin, SCIM, Audit Logs and Status APIs
IntegrationsMore than 2,600 apps listed by Slack
Free planYes
Free trialPro and Business+ trials available for eligible workspaces
Free-plan history90 days of searchable messages and files
AcquisitionSalesforce completed acquisition on July 21, 2021
Security and complianceIncludes ISO 27001, ISO 27017, ISO 27018, ISO 27701, ISO 42001 and SOC 2 Type II attestations
Primary collaboration modelChannels, direct messages, huddles and shared external conversations
Visual preview

Demo & Screenshots

Screenshots are not available yet.TechZella will add verified product images when suitable official screenshots are found.
Our evidence-based assessment

TechZella Score

A proprietary editorial score based on product capabilities, usability, value, performance, support and user sentiment evidence.

8.6/10Moderate confidence
Features9.1
Ease of Use8.7
Value for Money8.0
Performance8.6
Support7.9
User Sentiment8.7

Slack offers mature messaging, huddles, canvases, workflow automation, AI features, extensive integrations and developer APIs. G2 reports a 4.5 out of 5 rating across more than 38,000 reviews. Free-plan retention and app limits reduce value for larger or archive-dependent teams.

Methodology v1.0. This is a TechZella editorial assessment, not a direct user-review average.

Independent review sources

Trusted Ratings

Ratings are published by the respective review platforms and may change over time.

Plans & pricing

Pricing

Free

$0
month

Free forever. Includes 90 days of searchable message and file access, limited app installations, file sharing and one-to-one huddles.

Check current pricing →

Pro

$8.75 monthly or $7.25 annually
per user per month

Adds unlimited message history, unlimited app integrations, group meetings and expanded Slack Connect capabilities.

Check current pricing →

Business+

$18 monthly or $15 annually
per user per month

Adds advanced AI features and expanded administration capabilities for growing organizations.

Check current pricing →

Enterprise+

Contact sales
custom

Enterprise plan with custom pricing and organization-level administration, security and compliance features.

Check current pricing →

Pricing may change. Verify current plans on the vendor's website.

Editorial assessment

Pros & Cons

Pros

  • Channel-based organization supports project, department and topic-focused communication.
  • Broad integration marketplace connects communication with business and developer tools.
  • Web, desktop and mobile access supports distributed and hybrid teams.
  • Huddles provide quick audio, video and screen-sharing sessions inside conversations.
  • APIs, webhooks, SDKs and Workflow Builder support custom automation.
  • Search, canvases and AI tools help users locate and summarize workspace information.

Cons

  • The Free plan limits searchable message and file access to 90 days.
  • Free workspaces may permanently delete content older than one year.
  • App-installation limits and feature restrictions vary substantially by plan.
  • Large workspaces require active notification, channel and permission governance.
  • Advanced AI, compliance and administration capabilities are concentrated in paid tiers.
  • External integrations can require separate subscriptions and administrator approval.
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