based on60,345 reviews

Slack Review

last updated February 25th, 2021
by Slack Technologies, Inc.
Layer 1
Offers free trial
based on60,345 reviews
Rating overview
All scores by reviewer
Rating overview
All scores by reviewer

Slack Pros and Cons


Lydia Pang

reviewed by

Lydia Pang


Real-time messaging
Offers a free version
Good for team collaboration
Supports video calling and file-sharing
Variety of third-party integrations
Easy to use


Light project planning features
No in-depth productivity features


Slack is a real-time collaboration and messaging platform that unifies all workplace communication into one tool. Besides instant messaging, users can also voice and video call each other, share documents, and screen-share. Slack allows plenty of third-party integrations such as Salesforce and Adobe Creative Cloud, ensuring that its native capabilities are supercharged for even greater results. It is also easy to use and is suitable for all companies looking for a robust work chat client. 

While it serves as a great tool for workplace communication, Slack does not replace a project management solution, however its lack of in-depth project management features such as shared calendars and to-do lists can be compensated for with third-party integrations. 

In this Slack review, we will explore project management features, pricing, ease of use, add ons, and more.

Slack Desktop and Mobile Direct Messaging Screenshot

What is Slack?

Slack is a team messaging tool developed by Slack Technologies and is an acronym for “Searchable Log of All Communication and Knowledge”. It started out as an internal collaboration tool for founder Stewart Butterfield’s online gaming company, Tiny Speck. Though initially designed for the MMORPG market, Slack immediately gained traction as an effective work chat client. In December 2020, the CRM giant Salesforce acquired Slack for $27.7 billion and created one of the biggest deals in the history of software acquisition. 

Today, over Slack is used by over 12 million customers and some of the companies that use Slack as a communication tool include Zendesk, Deliveroo, BBC, and IBM.

Facts and Figures

Customers Worldwide10000000
FounderStewart Butterfield, Cal Henderson, Eric Costello, Serguei Mourachov
HeadquartersSan Francisco, California
CEOStewart Butterfield

Slack Project Management Features

Slack is an essential team messaging tool that enables teams to have productive, real-time conversations in the workplace. With features such as instant messages, channels, and screen-sharing, teams can work with collaborators and clients inside and outside of the company. The Slack App Directory also boasts a wide variety of third-party integrations ranging from customer support to finance, ensuring that teams can integrate tools beneficial for their workflows. Finally, Slack’s open API also allows developers to build more add-ons and gives teams the ability to customize the platform even further.

Project Planning

Slack helps teams propel their projects forward by centralizing conversations, files, and tools in one accessible location. Though seldom used on its own, Slack is a useful addition to any project management toolkit. With Slack’s Workflow Builder and Slackbot, users can set date reminders, manage travel requests, schedule messages for the future, and update teammates on a project’s progress. These automations break down organizational silos and improve connectivity between tasks. 

How do other options score for project planning?

Workflow management streamlines business practices through automation and improves productivity within the organization. Slack’s Workflow Builder allows teams to create pre-built workflow routines that include approving travel requests, scheduling future messages, and updating teammates on a project’s status. Users can also take advantage of Slack’s workflow templates that can be accessed right within the Slack application. On the Standard and Plus plans, workspace owners and admins have the option to restrict workflow creation to just some members of their workspace. 

Slackbot, a chat robot implemented by Slack, also answers any question a user might have about using the app. It functions as a virtual personal assistant such as setting reminders for important dates or deadlines. Teams can add customized responses to questions in Slackbot - for example, “What is the Wi-Fi password?” - which simplifies the onboarding process.

Communication & Collaboration

Designed to be a work chat client, Slack functions well as a collaboration hub and boasts features suitable for team communication. From software development to marketing plans, Slack unifies all conversations that go along with managing small and big projects via instant messaging and Slack channels. Team members can also collaborate externally, take down notes, and send files to each other. 

How do other options score for communication & collaboration?

Well-known for its direct messaging features, Slack is a messaging app that provides teams a unified platform where all work-related communication can take place. Alongside direct messaging, Slack users can also create and communicate through “channels”, often for team conversations and updates. These channels can be set to public or private, invitation-only. Team members can also create group chats among specific users. 

To add additional context to instant messaging, users can also share files and use GIFs and emojis. Teams can also use Slack to voice call and video call each other, as well as holding group calls within entire channels and group chats. Within the call, users can annotate while screen-sharing to help express complex ideas more clearly. Fully featured apps for iOS and Android means that team members can stay in touch anytime, anywhere. 

If integrated with other apps such as Zoom and WebEx, users can start or join voice and video conferences without ever leaving Slack, further improving team communication.

Slack Messaging Screenshot

File Sharing

Though used primarily as a communication tool, Slack also helps teams store and share files and attachments in one place. Team members can send files to each other on Slack without any restrictions on file formats. On Slack’s free plan, the file storage limit for the entire workplace is 5GB, whereas each member on the Standard plan is limited to 10GB of storage. Third-party software such as OneDrive and Google Drive also further expand Slack’s native file-storing capabilities. Individual users can share files with each other, as well as within different channels. 

External collaboration helps teams develop better professional relationships with partners outside of the company. Teams can also use Slack within a company by creating their own communication avenues called “channels”. Channels allow project managers to assemble users in the right spaces so that information is passed down to the right team members. 

Channels can be public, private, or shared. Shared channels in particular are useful for external collaboration as vendors and clients can be added without having access to private channels. Project managers can also create single-channel or multi-channel guest accounts for external collaborators, permitting them to view only the channels relevant to them. Project managers can add a guest to their Slack workspace by entering his or her email address.


Slack offers users a personal space where they can take down notes and reminders for later use. Users can click on their own names in the direct messages list to open a chat window and type in notes. Slack also provides users the choice to format text according to the markdown style. Once the note has been composed and sent, it should immediately appear in the user’s personal space. 

Since Slack’s note-taking feature takes on the format of direct messages, it is currently not possible to structure and organize notes. 

Slack Pricing

Layer 1
Offers free trial

Pricing for Slack is structured as four plans: one free and three paid, all billed on a per-month basis. The free version of Slack provides great features at no cost, including channels, video conferencing, and access to the team’s 10,000 most recent messages. The Standard plan of Slack unlocks the team’s entire message history and an unlimited number of third-party apps. Both the free and Standard plans are suitable for small to medium-sized businesses. 

On the other hand, the Plus and Enterprise plans are geared towards large companies that require advanced features such as enterprise-grade security and compliance. The Plus and Enterprise plans also offer advanced identity management features such as SAML-based SSO and 24/7 customer support with a four-hour response time. All Slack subscriptions are billed on a monthly or annual basis. No matter the size of the team, Slack has an appropriate plan for every company.


Access to 10,000 of the team’s most recent messages
10 integrations with other apps like Google Drive, Office 365, and more
1:1 voice and video calls between teammates
Screen-sharing and file-sharing


from $8 per user, per month

All features of the free plan
Unlimited message archive
Unlimited apps and integrations
Group video calls up to 15 users
Work securely with other organizations with Slack Connect
OAuth with Google
Two-factor authentication settings
Custom retention policies for messages and files
Custom user groups for different teams and departments
Manage channel posting permissions for #general channel only
Channel recommendations
Organise channels, messages and apps into custom, collapsible sections
Priority support


from $15 per user, per month

All features of the Standard plan
Corporate exports of all messages
Choice of region for data residency
User provisioning and deprovisioning
Real-time Active Directory sync with OneLogin, Okta and Ping
24/7 support with 4-hour first response time
99.99% guaranteed uptime SLA
SAML-based single sign-on (SSO)

Enterprise Grid

Contact Slack for custom pricing

All features in the Plus plan
Unlimited workspaces
Organisation-wide search, messaging and announcement-focused channels
Support for integrations with data loss prevention (DLP), e-discovery and offline backup providers
Security, compliance, billing and platform integration management in a single view
Enterprise mobility management (EMM) integration
Audit log API
Designated account and customer success teams
HIPAA-compliant message and file collaboration

Slack Security

Slack is committed to the highest levels of privacy and data protection. It is GDPR-compliant and is certified in ISO/IEC 27001, ISO/IEC 27017, ISO/IEC 27018, SOC 2, SOC 3, and more. 

All data transmitted between Slack clients is encrypted with strong protocols, such as TLS 1.2 protocols and AES256 encryption. Data at rest is also encrypted using FIPS 140-2 compliant standards, and all encryption keys are stored in a secure server on a segregated network with limited access. 

In case of a technical failure, Slack uses a combination of storage technologies to ensure customer data is fully protected. Slack hosts its services in data centers surveillanced by industry-leading service providers that offer modern and adequate physical protection for servers. 

Slack ensures that only approved individuals and devices can access company information via features like single sign-on, domain claiming, and support for enterprise mobility management. When a company deletes its Slack account, data is removed immediately and Slack hard-deletes all information from production systems that are currently running. Backups are destroyed within 14 days.

Slack Integrations

Slack’s integrations with other project management apps are what make it such a versatile and effective tool. When coupled with other software solutions, its native functions expand greatly. Some third-party apps include:

  • Trello
  • Salesforce
  • Asana
  • Hubspot
  • Zapier
  • StackOverflow
  • Dropbox


Ease of use is where Slack really shines, thanks to its straightforward user interface. On the desktop app, users can find channels and conversation threads on the left. Functionally and aesthetically, the iOS and Android mobile apps mirror the desktop app and is easy to use with almost zero learning curve. There is also a clear division between channels, direct messages, and recent apps, providing clarity for the user. Slack’s settings and preferences allow further customization, such as light or dark mode and toggling notifications on and off. 

Slack also supports the usage of emojis and GIFs, making the working process fun and relaxing. The search function also enables important information to be found quickly. All the tools and features are intuitive and require little to no learning curve to learn.

Mobile Apps

While Slack can be used through the web app within a browser, it also has a desktop app. Slack also supports mobile apps for iOS and Android devices. The Slack app on both platforms share the same functionalities as the desktop app, enabling team members to use Slack both at work and on the go. Through the app, teams can send messages, start and receive calls, and send files and documents.


Slack offers users a variety of support options, including a help center that features helpful resources and tutorials. Users of all paid plans receive 24/7 support but with small distinctions:

  • Slack Free: standard support with form submission, response time is typically within an hour

  • Slack Standard: 24/7 support

  • Slack Plus: 24/7 support with four-hour first response time

  • Slack Enterprise: 24/7 priority support with four-hour first response time

Slack Alternatives

As an instant messaging tool with strong collaboration features, Slack can be a solid companion to other project management solutions such as:


Slack is a popular team collaboration tool that centralizes all workplace communication in a single location, ensuring discussions and feedback flow smoothly. Its collaboration features such as instant messaging, direct messages, channels, voice and video conferencing make it a great addition in the workplace. It boasts many third-party integrations that expand the local features of Slack. 

However, once a user upgrades from a free plan to a paid plan, the cost increases. The lowest-tier paid plan, Slack Standard, costs $6.67 per user, per month if billed annually. It is also light on project management features, but this can be made up for with third-party integrations.


Over 12 million people use Slack as an online collaboration tool and messaging app. It replaces emails as the main channel of communication and allows team members to share messages, files, and documents all in one app. 


Yes, Slack comes in a free version that includes access to the team’s last 10,000 messages and a limit of 10 third-party integrations. It is nevertheless a useful messaging platform suitable for team collaboration.


Slack offers a lot of advantages and benefits but does not completely replace a project management tool. Here are other apps that have an in-built messaging platform: Basecamp, Salesforce, Zoho Projects, ScrumGenius, Teamwork.com.