Slack Suffers Widespread Global Outage, Users Frustrated

Workplace communication platform Slack was hit with a widespread service disruption on Wednesday, May 27, 2026, leaving thousands of users across multiple continents unable to connect. The outage, which affected critical features like messaging and notifications, underscored the platform's vital role in daily business operations and sparked considerable frustration among its global user base.

Reports of issues began to surface shortly before 11:30 p.m. local time in the U.K. and Australia, while users in the U.S. started experiencing problems during the afternoon hours. Downdetector, a service tracking user-submitted outage reports, quickly reflected the growing crisis. Initially logging around 2,800 complaints, the number rapidly surged past 6,000 within approximately an hour by early evening, and by mid-morning on May 28, Downdetector was tracking over 15,000 reports.

Slack's official status page, which initially showed no reported issues, was eventually updated to acknowledge the severe disruption. The company described the incident as "severe latency impacting all Slack services." The range of affected functionalities was extensive, encompassing essential features such as messaging, login and single sign-on authentication, notifications, search, workspace administration, file sharing, huddles, workflows, apps and integrations, and general connectivity. Many users specifically pointed to messages failing to send and difficulties with attachment functionality, noting impairments on both desktop and browser versions, though some found partial functionality on the mobile app.

Throughout the disruption, Slack's engineering team actively investigated the problem and provided continuous updates. By 4:31 PM PDT on May 27, the company announced it was "implementing fixes" and observed "some improvements." Further progress was reported at 6:03 PM PDT, indicating that most features, with the exception of Workflows and Messaging, had largely recovered. However, some lingering impacts were noted, including issues like empty pills instead of @-mentions, delayed reacji, mismatches in channel member counts, and slow loading of messages, user avatars, and unfurls. Messaging functionality was fully reported as recovered by 6:41 PM PDT, and by 7:17 PM PDT, messaging latency had cleared, though the company cautioned that workflows triggered during the impact period, ending around 7 PM PDT, might not have completed as expected.

The specific cause of the disruption was not publicly identified by Slack at the time of initial reporting, nor was an estimated time for full resolution provided beyond the incremental recovery updates. The incident highlighted the complex infrastructure required to maintain seamless global communication for millions.

Public reactions poured in across various platforms, with users taking to Downdetector and social media, including X, to voice their frustrations. One user on Downdetector reported, "Currently getting 'Couldn't send message' when I attempt to attach a screenshot to a message in Slack. My colleagues are also having this issue." Another user on X reportedly stated, "slack going down for 30 minutes was like the apocalypse for tech startups. @SlackHQ PLEASE dont scare me like that again." Other observations included difficulties editing or deleting messages and attachments failing to display correctly. A user, Gesi Lloyd, was credited in one report detailing the outage, noting the desktop app was not receiving messages while the phone app worked for them. The sentiment was clear, with one user even quipping that "Slack being down is a sign to head home for the day."

This May 27 outage is not an isolated incident for Slack, which has faced several service disruptions in recent times. Just over two months prior, on March 12, 2026, the platform experienced a significant global outage that lasted for 2 hours and 27 minutes, affecting an estimated 18.2 million active users. That prior incident was attributed to a misconfiguration in Istio 1.22's circuit breaker settings for the chat-api service, which led to the mass ejection of healthy backend pods. The March outage impacted core functionalities such as sending and receiving messages, thread replies, message reactions, file uploads, shared canvas access, huddles, and workflow automations, resulting in $2.3 million in automatic SLA credits for enterprise customers.

Further compounding these issues, Slack also encountered a service disruption on May 14, 2026, which primarily affected messaging capabilities and various third-party applications and integrations. Monitoring services additionally indicated warnings for Slack outages on May 8, May 11, May 19, and May 28, 2026, in addition to the more widely reported May 14 and May 27 events. These recurring incidents underscore the immense challenge of maintaining a robust, always-on communication platform that is now central to global professional workflows. For countless organizations, a disruption to Slack means a direct hit to productivity and operational continuity, making each outage a critical event for the modern workplace.