Outage report · Partial outage

Slack outage on Oct 1, 2026

Incident: Free Plan Customers Are Experiencing Message Failures

SeverityPartial outage

StartedOct 1, 2026, 12:39UTC

ResolvedOct 1, 2026, 18:59UTC

Duration6h 20m

What happened

Slack reported a partial outage starting Oct 1, 2026, 12:39 UTC. It was marked resolved at Oct 1, 2026, 18:59 UTC.

The incident lasted 6h 20m from first report to resolution.
Slack had reported 4 other partial or major outages in the 90 days before it.
12 other vendors we track reported a significant incident within 12 hours of it.

Latest update from Slack

5:39am PDT We're aware that some customers on our free plan are experiencing message-sending limit blocks in an unusual spike pattern, which is preventing them from sending messages. We're investigating why this message limit was triggered unexpectedly for some teams. If you're affected, you may be temporarily unable to send messages until this is resolved. We'll provide an update in 30 minutes or sooner if additional information becomes available. 5:56am PDT We identified that a third-party app is stuck in a loop that has triggered billions of messages. This is causing free plan users to exceed messaging limits. We apologize for the inconvenience and will provide another update as soon as we have more details to share.  6:58am PDT A feature toggle ramp-up caused an app integration to repeatedly post messages in a processing loop. This pushed free plan customers over the message volume threshold, triggering the sending block. We're working to restore access and are activ

Read Slack's official incident report ↗