Klaviyo Outage History

Klaviyo experienced a 3.9-hour incident where SMS event processing was delayed by 2-3 hours, affecting analytics, segmentation, flow triggering, and reporting while SMS message delivery continued normally. The delays impacted SMS event-triggered flows, real-time segments built on SMS data, and caused some customers to encounter errors when creating RCS agents and viewing videos. The engineering team identified and resolved the root cause, restoring real-time SMS event processing by 6:38 PM ET on May 19, 2026.

Klaviyo customers experienced intermittent errors and slow page loads in the app, along with delays of up to 20 minutes for email and SMS sends and delays in push notification flows. The incident affected multiple components including the main app, campaign sending, flow sending, and various SMS/MMS services. The engineering team identified the root cause, deployed a fix, and resolved all issues within 1.5 hours, with a small number of affected push notifications being replayed.

Klaviyo experienced a 9.5-hour incident where users encountered errors loading campaign and flow pages, though email sending functionality remained operational throughout. The issue was caused by AWS infrastructure instability combined with increased retry traffic, which also resulted in analytics processing delays of approximately 2 hours. The incident was fully resolved with analytics processing returning to normal operation and all affected components restored.

Klaviyo experienced a 17.6-hour service disruption caused by AWS infrastructure instability that affected analytics, reporting, segmentation, flows, and campaigns. Users encountered loading errors on flows and campaigns pages, segmentation delays of approximately 1.5 hours, outdated analytics data, and issues with segment-triggered flows and campaign audience targeting. The incident was resolved with all services restored to real-time processing, and no data was lost during the outage.

Klaviyo experienced a major service disruption lasting 49.7 hours that affected access to klaviyo.com, APIs, and message sending across all core platform functions including email campaigns, mobile push notifications, analytics, and user login capabilities. The outage prevented customers from logging in, sending campaigns or flows, and processing events during the incident period. All services were fully restored with klaviyo.com access returning first, followed by progressive recovery of dependent services, and final completion of background data reconciliation and integration repairs.

Klaviyo experienced intermittent API errors starting at 2:27 AM US/Eastern on 04/25/2026, causing customers to encounter 503 errors when logging in, loading pages, or making API requests. The engineering team identified the root cause and implemented a fix at 3:20 AM US/Eastern that restored all API functionality. The incident was fully resolved after 50 minutes, with customers needing to retry any requests that failed during the outage window.

Klaviyo experienced delays in real-time segment processing starting at 8:15 PM US Eastern on March 26th, affecting a subset of customers with segments becoming out of date by up to 2.5 hours. The engineering team identified and implemented a solution within 33 minutes. Real-time segmentation functionality was fully restored and returned to normal processing speeds.