The Slack messaging tool suffered a major outage today that left users unable to connect to the service. In a post on its systems status page, Slack reported that their customers were experiencing connectivity issues as a result of the outage:

“A majority of customers are unable to connect to Slack. We’re aware of the issue and are working to resolve it as quickly as possible…We’ve isolated the problem and are working on bringing the service back online for all users. More details to come as they become available.”

Later this afternoon they reported that most customers should be reconnected. They didn’t reveal the cause of the connectivity issues, but they were able to restore the service 45 minutes after noting the outage.

Users went on Twitter to discuss what some jokingly referred to as “The Great Slack Outage of 2018.”

How Slack Works

Slack is a cloud-based messaging application designed for business teams that need to collaborate. Slack helps users see what’s going on in the entire organization. It’s an internal messaging platform designed to make work simpler and more productive. Users can stay in constant contact with others at all hours.

Slack teams work together in channels that can be organized by project, department, office location, and more. It builds a searchable archive of a team’s conversations, decisions, and work; and over time becomes more useful due to its machine-learning capabilities. It integrates with nearly every enterprise and productivity application available today.

Everything shared in Slack is automatically indexed and archived so a business can create a comprehensive knowledge base with zero effort, simply by working in Slack. And, Slack’s search makes it easy find the information business users need. It centralizes notifications, files, and data from hundreds of different applications. What this means is that there’s no need to search through emails for information or use dozens of tools each with their own login. Slack provides all of the information and context needed to make effective decisions quickly.


Slack team administrators allow communities, groups, or people to join their team through a specific URL or by invitation. Slack was originally used for organizational communication, but it has been now turned into a community platform replacing message boards and social media such as Facebook or LinkedIn groups. These communities are categorized by topics that a group of people is interested in.

With Slack, team members can communicate without using email or group SMS (texting). Teams are open to anyone invited to join by the administrator. Private channels allow for conversations between smaller parts of the overall group so admins can break up large teams into smaller projects.

Direct messaging allows users to send private messages to a specific user rather than a group of people. Direct messages can include up to nine people (the admin and eight more). A direct message group can also be converted to a private channel.

Slack advertises itself as free for an unlimited number of users, but it was reported that the limit is actually 8,462 users per channel. However, users can upgrade to different paid versions to gain access to larger channels and additional features.

Slack provides mobile apps for iOS, Android, and Windows Phone (beta), along with their web-browser client and native desktop clients for macOS, Windows, and Linux (beta). Apple Watch users can also use Slack to send direct messages, see comments, and make simple replies.

Slack Technologies

Launched in 2013, Slack is considered one of the fastest-growing business applications in history with 9 million active users, and 50,000 companies including a range of government agencies and private companies that pay to use its service. Its home office is located in San Francisco, but they have offices around the world.

The company originally raised nearly $43 million in April 2014, in October 2014 they raised another $120 million, and in March 2015 another $160 million. At that point, they were valued at $2.76 billion. Since then they’ve raised another $360 million. Amazon was interested in acquiring the parent company in 2017. It’s now valued at around $9 billion.

The Financial Times reported in March 2015 that Slack was the first business technology to have crossed from business into personal use since Microsoft Office and the BlackBerry.  Slack was recognized as the best startup of the year at the 10th Crunchies Awards, organized by TechCrunch.

Slack Has Had Problems Before.

Slack announced that it had been hacked over the course of four days in February 2015 and that some of their users’ data were compromised. This information included email addresses, usernames, hashed passwords, and, in some cases, phone numbers and Skype IDs. Afterwards, Slack added two-factor authentication to their service.

During the outage today, “Slack” was the #1 trending topic on Twitter. Users joked about how the outage may force them to actually talk face-to-face with their co-workers. Another example of how technology is changing our culture today