Klaviyo: Widespread Access Outage

Impact: criticalStatus: resolvedStarted 2025-10-20 08:58 UTCResolved 2025-10-21 17:06 UTC (32 h)13 updatesSource: stspg.io

Summary

Klaviyo reported a critical outage affecting login, sending and other services, caused by an upstream provider outage. The incident started at 2025-10-20 08:58 UTC and lasted 32 h 7 min, disrupting access and delaying sending, segmentation, unsubscribes and conversion attribution analytics. All services were restored, with resolution recorded at 2025-10-21 17:06 UTC.

Machine-written from the archived incident (Sol). Check the timeline before relying on it.

Affected components: AnalyticsBigCommerceIntegrations - Integrations - BigCommerceKlaviyo.comKlaviyo MarketingEmail Sending - Email ContentEmail SendingEmail Sending - Flow Email SendingSMS Sending - SMS Sending - Toll Free Number SMSIntegrations - Integrations - MagentoMobile Push SendingProfilesSMS Sending - SMS Sending - OtherText Message SendingIntegrations - Integrations - ShopifyShopifySMS Sending - SMS DeliverabilityText Message DeliverabilitySMS Sending - SMS Number ProvisioningSegmentationSegmentsSMS Sending - SMS ContentIntegrations - Integrations - Magento 2MagentoIntegrations - Integrations - WooCommerceWooCommerceConsent PagesUnsubscribe & Preference PagesKlaviyo AppKlaviyo App - Klaviyo AppReviewsSign-up FormsSignup FormsFlow TriggeringProcessingIntegrations - Integrations - OtherOtherEmail DeliverabilityEmail Sending - Email DeliverabilitySMS Sending - SMS Sending - Short Code SMSListsList SubscriptionKlaviyo APIServer-sideSMS Sending - SMS Sending - Toll Free Number MMSSMS Sending - SMS Sending - Short Code MMSEmail SendingEmail Sending - Campaign Email Sending

Timeline of updates

investigating2025-10-20 08:58 UTC
Starting around 2:50am EST, due to outages with an upstream provider, several services in Klaviyo including log-in and sending are inaccessible. We'll provide updates as soon as more information is available.
monitoring2025-10-20 09:58 UTC
As of 5:30am EST, the ability to log in and access the Klaviyo app has been restored. Restoration of all functionality and services is in progress. We are actively investigating the state of sending (campaigns, flows). We will continue to monitor services as functionality is repaired and will share updates as we make progress.
monitoring2025-10-20 10:41 UTC
As of 6:15am EST, we are continuing to stabilize our systems and process any actions that were affected by the provider outage, which lasted from approximately 2:50 to 5:30am EST. We are attempting to send any campaigns and flows messages that couldn't be sent during that time. We are also processing events and profile information received during that time. Data from API requests that received an error during the incident were lost. We will continue to share updates as we make progress.
monitoring2025-10-20 12:39 UTC
As of 8:30am EST, we have successfully sent the delayed campaign and flow messages. Over the next several hours, we will process delayed conversion attribution analytics and delayed profile unsubscribes. We continue to closely monitor our systems.
monitoring2025-10-20 15:09 UTC
We continue to process delayed conversion attribution analytics and delayed profile unsubscribes. We are currently experiencing delays in segmentation processing for a subset of users by up to 60 minutes. We’re working to mitigate these processing delays as quickly as possible.
monitoring2025-10-20 15:26 UTC
Segmentation processing has been restored. We continue to work through processing for the delayed analytics and unsubscribes.
investigating2025-10-20 16:46 UTC
We are currently investigating an issue impacting flow sending beginning around 12:00 PM US/Eastern. We’ll provide updates as soon as more information is available.
investigating2025-10-20 17:37 UTC
We are currently experiencing delays in segmentation processing for a subset of users by up to 2.5 hours. We’re working to mitigate these processing delays as quickly as possible.
identified2025-10-20 18:55 UTC
A mitigation has been deployed for the issue impacting flow sending. Any delayed messages are now being replayed and flow performance is improving. We will confirm once this has been fully restored. The team continues to work through the segmentation processing delays. We continue to monitor closely and appreciate your patience throughout this incident.
monitoring2025-10-20 20:21 UTC
Segmentation processing has been restored to real-time. Segments relying on custom object properties remain delayed and we're continuing to restore normal processing for these. We expect flow sending to be fully caught up within the next hour. We continue to process delayed conversion attribution analytics and delayed profile unsubscribes.
monitoring2025-10-20 20:45 UTC
Flow sending is fully caught up and restored to real-time. We continue to process delayed conversion attribution analytics and delayed profile unsubscribes.
monitoring2025-10-21 00:31 UTC
As of 7:32pm EST, we have successfully processed the delayed unsubscribe events and conversion attribution analytics has been restored. We continue to monitor service functionality as repairs have been completed.
resolved2025-10-21 17:06 UTC
All services have been restored and are operating normally. Monitoring is complete, and this incident has been resolved. We appreciate your patience throughout this incident.

Rewindex changes for this incident

Critical incident: Widespread Access Outage 2025-10-20 08:58 UTC

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