Marketing Automation & CDPs · reliability comparison
Customer.io vs Klaviyo: which is more reliable? (2026)
Customer.io is more reliable than Klaviyo, scoring 96.2 vs 62.2 out of 100. Over the last 90 days Customer.io reported 5 incidents and Klaviyo reported 13, with effective uptime of 99.99% and 99.26% respectively. Customer.io resolves incidents faster on average (19m).
Data updated Nov 1, 2026 · How we score
| Metric | Customer.io | Klaviyo |
|---|---|---|
| Reliability score | 96.2 | 62.2 |
| Rank (marketing automation platforms) | #1 | #11 |
| Uptime (90 days) | 99.99% | 99.26% |
| Incidents (90 days) | 5 | 13 |
| Partial / major outages | 0 | 5 |
| Avg time to resolve | 19m | 3h 39m |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Customer.io and Klaviyo differ
- Klaviyo reported 2.6× as many incidents as Customer.io over the last 90 days (13 vs 5).
- Klaviyo had 5 partial or major outages, compared with 0 for Customer.io.
- Customer.io fixes problems faster: 19m on average, against 3h 39m for Klaviyo (11.6× quicker).
- Customer.io's longest outage on record lasted 2h 42m (Jun 13, 2026); Klaviyo's lasted 2d 1h (May 5, 2026).
90-day uptime
Customer.io
Klaviyo
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Recent Customer.io incidents
- Degraded performanceOct 27, 2026 · resolved in 25m
Customer.io UI is currently unavailable for some customers
Affected: Management Interface
- Degraded performanceSep 19, 2026 · resolved in 27m
Some US customers may experience delays in message sending
Affected: Message Sending
- InformationalSep 4, 2026 · resolved in 1h 19m
Reduced Deliverability to Microsoft-Hosted Email Addresses
Affected: Message Sending
- Degraded performanceSep 3, 2026 · resolved in 5m
- InformationalAug 5, 2026 · resolved in 26m
Customer.io UI is inaccessible
Affected: Management Interface
Recent Klaviyo incidents
- Partial outageOct 29, 2026 · resolved in 2h 10m
Campaign Sending Delaysofficial update ↗
Affected: Email Sending, Text Message Sending, WhatsApp Sending, Mobile Push Sending
- InformationalOct 28, 2026 · resolved in 23h 43m
Affected: Email Sending, Text Message Sending, WhatsApp Sending, Mobile Push Sending, Processing
- Partial outageOct 22, 2026 · resolved in 14h 47m
Outbound Webhook Delaysofficial update ↗
Affected: Analytics
- Partial outageOct 17, 2026 · resolved in 4h 49m
Flow Sending Delaysofficial update ↗
Affected: Email Sending, Text Message Sending, WhatsApp Sending, Mobile Push Sending, Flow Editor, Processing
- Degraded performanceOct 9, 2026 · resolved in 2h 6m
Analytics Events Processing Delays
Affected: Segments, Profiles, Analytics
- Major outageOct 8, 2026 · resolved in 1h 13m
Login and page loading issuesofficial update ↗
Affected: Klaviyo App
Other marketing automation platforms to consider
- HubSpot Marketing Hub · #2 · 100% uptime
- Iterable · #3 · 99.96% uptime
- RudderStack · #4 · 99.94% uptime
- Hightouch · #5 · 99.92% uptime
See the full most reliable marketing automation & customer data platforms ranking →