Slack outage history

Impact began at 12:40 PM UTC as free-plan users faced message-sending limit blocks during a spike in activity, with some teams unable to send messages. A third-party app was stuck in a loop that generated billions of messages across free-plan workspaces, contributing to the disruption. Slack later traced the root cause to a feature toggle ramp-up that caused an app integration to repeatedly post messages. A fix was identified by 2:34 PM UTC and deployment of the remedy began around 6:59 PM UTC; access was being restored and the incident was resolved by 7:04 PM UTC.

Slack admins experienced trouble using the Search bar on org dashboards, hindering tasks like locating users or channels. The issue began around 9:00 PM UTC and Slack documented a degraded experience for the Search component on org dashboards.

Slack identified the cause as a recent change and initiated a rollback to restore functionality. The Search bar returned to normal by 12:39 AM UTC as the rollback took effect, marking the incident as resolved.

Slack users relying on inbound emails to post into Slack channels experienced degraded email delivery beginning at 2:19 AM UTC. The disruption affected the Apps/Integrations/APIs component and prevented incoming emails from appearing in Slack, disrupting email-to-Slack workflows for about an hour and a half. Slack documented the issue as a feature degradation while investigating the email ingestion pipeline.

Slack users attempting to trigger messages in channels via certain Workflows that reference a message link were unable to post, receiving an Input Validation Error. The issue affected the Workflows component and degraded automation for affected users. The incident began at 8:29 AM UTC as Slack acknowledged the problem and began investigation.

An initial analysis pointed to a conflict between specific variables introduced by a recent change. A test of reverting that change appeared to resolve the issue, and a production-wide revert was rolled out to restore functionality. The Workflows component returned to normal by 10:50 AM UTC.

Some Slack users experienced issues with receiving reminder notifications, starting around 2:19 AM UTC. Reminders were not delivered as scheduled, disrupting workflows for those relying on automated alerts. The impact was limited to the Notifications component rather than a full Slack outage. The incident was resolved after about an hour as the team investigated and implemented a fix.

Slack’s status page indicated the cause was identified and a change deployed to address the issue, with monitoring ongoing. A fix was deployed around 2:54 AM UTC, and the service returned to normal by 3:25 AM UTC.

During Slack's Android app rollout, submitting workflow forms that include file attachments on Android experienced issues, impacting the Workflows component for affected users. The disruption began at 5:54 PM UTC and persisted as the rollout progressed, with Slack continuing to monitor and provide updates. The issue was resolved by 8:44 PM UTC as the rollout completed and status returned to normal.

The Slack Messaging component experienced a degradation in email delivery that prevented some users from receiving email confirmation codes and invitations. As a result, affected users could not complete email-based login or accept invitations. The outage began at Feb 25, 2026 12:29 AM UTC and was resolved by Feb 25, 2026 4:54 AM UTC, lasting roughly 4 hours and 25 minutes.

Slack issued a series of status updates from the incident start through resolution, detailing investigation progress, root causes, and fix rollout. The final update noted that the Messaging component had recovered. In total, Slack published 6 status updates during the incident, with root causes including a suppression list subtype causing blocks and a missing data field in the email validation system before the fix was deployed.

Slack experienced a disruption impacting Direct Messaging, with users unable to add people to multi-person direct messages and some errors when sending messages. The issue affected Slack's Messaging component and persisted for several hours. The outage began on 2:39 PM UTC and was resolved by 7:24 PM UTC, for a duration of roughly 4 hours and 45 minutes. Users reported difficulties with direct messaging during the incident, and some updates noted ongoing investigation and stabilization efforts.

Slack experienced a prolonged connectivity outage that prevented many users from accessing Slack via web browsers and impacted app integrations relying on Incoming Webhooks. The incident began at Feb 18, 2026 10:44 AM UTC and persisted for about 37 hours, ending with services restored at Feb 20, 2026 12:29 AM UTC. In addition to general access issues, Slack noted that Incoming Webhooks could silently fail during app installations, affecting certain Apps/Integrations/APIs during the early phase of the incident. The outage affected multiple regions as users reported access problems across different networks.

Slack issued four official updates during the incident. The initial update at Feb 18, 2026 10:44 AM UTC marked a transition from a nominal connectivity state to a degraded condition. A second update at Feb 18, 2026 2:04 PM UTC warned about issues generating Incoming Webhooks and moved Apps/Integrations/APIs to warn. The third update at Feb 18, 2026 6:34 PM UTC described users unable to access Slack via various browsers, with antivirus conflicts noted, and Apps/Integrations/APIs improving to up. The final update at Feb 20, 2026 12:29 AM UTC indicated Connectivity had returned to up.

Overall, the incident showed a prolonged connectivity problem with some API integration issues resolving sooner; however, the primary access interruption endured for most of the event, prompting ongoing monitoring of service availability.

Slack experienced a brief connectivity incident that affected a subset of Slack workspaces. Users reported intermittent access to messages and channels during the event. The outage began at Feb 12, 2026 11:09 PM UTC and was resolved by Feb 12, 2026 11:30 PM UTC, lasting about 21 minutes.

The Slack status page issued 2 updates during the incident. The first update indicated that a subset of workspaces were affected and that engineers were actively investigating. The second update announced that connectivity had been restored and services were returning to normal.