Changes / Klaviyo / Widespread Access Outage
Klaviyo: Critical incident: Widespread Access Outage
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 diff below (Sol; type: incident outage). Check the diff before relying on it.
What changed
Before: not present
After: Widespread Access Outage
Before: not present
After: critical
Before: not present
After: resolved
Before: not present
After: 2025-10-20 08:58 UTC
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After: 2025-10-21 17:06 UTC
Before: not present
After: Analytics, BigCommerce, Consent Pages, Email Deliverability, Email Sending, Email Sending - Campaign Email Sending, Email Sending - Email Content, Email Sending - Email Deliverability, Email Sending - Flow Email Sending, Flow Triggering, Integrations - Integrations - BigCommerce, Integrations - Integrations - Magento, Integrations - Integrations - Magento 2, Integrations - Integrations - Other, Integrations - Integrations - Shopify, Integrations - Integrations - WooCommerce, Klaviyo API, Klaviyo App, Klaviyo App - Klaviyo App, Klaviyo.com, Klaviyo Marketing, Lists, List Subscription, Magento, Mobile Push Sending, Other, Processing, Profiles, Reviews, Segmentation, Segments, Server-side, Shopify, Sign-up Forms, Signup Forms, SMS Sending - SMS Content, SMS Sending - SMS Deliverability, SMS Sending - SMS Number Provisioning, SMS Sending - SMS Sending - Other, SMS Sending - SMS Sending - Short Code MMS, SMS Sending - SMS Sending - Short Code SMS, SMS Sending - SMS Sending - Toll Free Number MMS, SMS Sending - SMS Sending - Toll Free Number SMS, Text Message Deliverability, Text Message Sending, Unsubscribe & Preference Pages, WooCommerce
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: Segmentation processing has been restored.
We continue to work through processing for the delayed analytics and unsubscribes.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: 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.
Before: not present
After: Flow sending is fully caught up and restored to real-time.
We continue to process delayed conversion attribution analytics and delayed profile unsubscribes.
Before: not present
After: 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.
Before: not present
After: 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.
First version of this incident archived by Rewindex. View the live incident (opens in new tab).
History of this incident
| When (UTC) | Change | Kind |
|---|---|---|
| Critical incident: Widespread Access Outage (this change) 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. | Major incident |