Companies / Klaviyo / incidents

Klaviyo: Data processing delays

Affected components: Email SendingEmail Sending - Flow Email SendingSegmentationSegmentsKlaviyo AppKlaviyo App - Klaviyo AppFlow TriggeringProcessingKlaviyo APIServer-sideEmail SendingEmail Sending - Campaign Email Sending

Timeline of updates

1. investigating2025-12-18 04:10 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. identified2025-12-18 05:12 UTC

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

3. monitoring2025-12-18 06:06 UTC

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

4. resolved2025-12-18 06:36 UTC

   This incident has been resolved.

Impact, status and times are the vendor’s own, as last archived. View on stspg.io (opens in new tab). Klaviyo profile · Recent Klaviyo incidents · Markdown · JSON