The Stakes of Communication Platform Downtime

When your team's communication tool goes down, it doesn't just stop chat — it disrupts your entire incident response capability. If you're using Slack or Teams to coordinate during outages, and that tool itself goes down, you're flying blind.

At ServiceAlert.ai, we monitor both Slack and Microsoft Teams around the clock. Here's what we've observed about their reliability.

Uptime Track Record

Slack

Slack has maintained strong uptime historically, but has experienced notable incidents:

  • Typical uptime: 99.95%+ in most months
  • Common issues: API degradation, message delivery delays, file upload failures
  • Architecture: Runs on AWS, with incidents often correlating to AWS issues
  • Status page: status.slack.com — generally transparent and timely

Microsoft Teams

Teams is deeply integrated with the Microsoft 365 ecosystem, which is both a strength and a vulnerability:

  • Typical uptime: 99.9%+ in most months
  • Common issues: Authentication failures (tied to Azure AD), meeting join issues, presence status delays
  • Architecture: Runs on Azure, tightly coupled with Exchange, SharePoint, and Azure AD
  • Status page: status.office.com — covers all of M365, not just Teams

Key Differences in Outage Patterns

Blast Radius

Slack: Outages tend to be isolated. When Slack goes down, it's usually just Slack. Your email, files, and other tools continue working.

Teams: Because Teams is woven into Microsoft 365, a Teams outage often means Outlook, SharePoint, and OneDrive are also affected. An Azure AD issue can take down authentication across all Microsoft services simultaneously.

Recovery Speed

Slack: Typically recovers within 1-2 hours for major incidents. Their engineering team posts frequent status updates during incidents.

Teams: Recovery can be slower due to the complexity of the M365 ecosystem. A single root cause can require fixes across multiple interconnected services.

Communication During Outages

Slack: Uses status.slack.com and Twitter/X for updates. Generally provides detailed post-incident reports.

Teams: Updates via the Microsoft 365 Service Health Dashboard. Post-incident reports are available but can take longer to publish.

Which Should You Choose?

From a reliability perspective alone, both platforms are highly available. The more important question is: what's your backup plan?

Our Recommendations

  • Don't rely on a single communication tool for incident response. If you use Slack, have a Teams bridge (or vice versa). At minimum, keep a phone tree or SMS group.
  • Monitor both with ServiceAlert.ai — get instant alerts when either platform has issues so you can switch to your backup channel immediately.
  • Consider the ecosystem risk. If your organization is all-in on Microsoft 365, a Teams outage likely means your email is down too. Slack, being more isolated, may be the better choice for incident response channels.
  • Test your failover plan. Run a quarterly drill where you simulate your primary communication tool being down.

    • Bottom Line

    Slack edges ahead slightly on isolated reliability and transparency during incidents. Teams offers deeper integration but carries ecosystem risk. The winner for your organization depends on your broader tool stack and how well you've planned for communication tool failure.

    The real answer? Monitor both, plan for failure, and never let a communication outage leave your team unable to coordinate.

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