Klaviyo: API 503 Errors
Klaviyo's status page listed this on 26 Apr 2026. Lasted 47 min, filed against Server-side. This is their record, not a measurement of ours.
What happened
Started
Resolved
Lasted47 min
What failedServer-side
Their impactMinor
Regions: their page does not say which. Ours checks from three cities, and the screen we saw is on our own incident pages, where there is one.
What Klaviyo said
On their page: API 503 Errors
Klaviyo's status page: “Starting at approximately 2:27 AM US/Eastern on 04/25/2026, we began experiencing intermittent elevated errors across our APIs. Some customers may experience 503 errors when trying to log into Klaviyo, load certain pages or make API requests. Our Engineering Team has identified the root cause and has implemented mitigations. We'll provide updates as soon as more information is available.”Identified
Klaviyo's status page: “We successfully implemented a fix as of 3:20 AM US/Eastern that restored all API activity. We are continuing to monitor the results.”Monitoring
Klaviyo's status page: “We confirmed that all API activity has been stable since the fix was released. Any requests that returned 503 errors during the outage window will need to be retried. This incident has been resolved.”Resolved
What our own check saw
Nothing of ours failed that day, or we were not checking Klaviyo yet.
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