Klaviyo incident

Data processing delays

Minor Resolved View vendor source →

Klaviyo experienced a minor incident on December 18, 2025 affecting Klaviyo App and Campaign Email Sending and 1 more component, lasting 2h 25m. The incident has been resolved; the full update timeline is below.

Started
Dec 18, 2025, 04:10 AM UTC
Resolved
Dec 18, 2025, 06:36 AM UTC
Duration
2h 25m
Detected by Pingoru
Dec 18, 2025, 04:10 AM UTC

Affected components

Klaviyo AppCampaign Email SendingKlaviyo APIFlow Email SendingSegmentationFlow Triggering

Update timeline

  1. investigating Dec 18, 2025, 04:10 AM UTC

    Starting around 9:52pm US Eastern, a database upgrade failure caused data processing delays in-app. As a result, we are experiencing delays in event processing, flows, unsubscribes, segmentation, sending for certain campaigns, and v3 APIs. No data loss is expected. We are actively working to resolve the incident and will provide updates when possible.

  2. identified Dec 18, 2025, 05:12 AM UTC

    The issue has been identified and a fix is being implemented.

  3. monitoring Dec 18, 2025, 06:06 AM UTC

    A fix has been implemented and we are monitoring the results.

  4. resolved Dec 18, 2025, 06:36 AM UTC

    This incident has been resolved.