Email Marketing Platforms · reliability comparison
Campaign Monitor vs Klaviyo: which is more reliable? (2026)
Klaviyo is more reliable than Campaign Monitor, scoring 62.2 vs 59.2 out of 100. Over the last 90 days Campaign Monitor reported 1 incident and Klaviyo reported 13, with effective uptime of 99.50% and 99.26% respectively. Klaviyo resolves incidents faster on average (3h 39m).
Data updated Nov 1, 2026 · How we score
| Metric | Campaign Monitor | Klaviyo |
|---|---|---|
| Reliability score | 59.2 | 62.2 |
| Rank (email marketing platforms) | #12 | #11 |
| Uptime (90 days) | 99.50% | 99.26% |
| Incidents (90 days) | 1 | 13 |
| Partial / major outages | 0 | 5 |
| Avg time to resolve | 3d | 3h 39m |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Campaign Monitor and Klaviyo differ
- Klaviyo reported 13× as many incidents as Campaign Monitor over the last 90 days (13 vs 1).
- Klaviyo had 5 partial or major outages, compared with 0 for Campaign Monitor.
- Klaviyo fixes problems faster: 3h 39m on average, against 3d for Campaign Monitor (19.7× quicker).
- Campaign Monitor's longest outage on record lasted 1h 9m (Jul 16, 2026); Klaviyo's lasted 2d 1h (May 5, 2026).
90-day uptime
Campaign Monitor
Klaviyo
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
Recent Campaign Monitor incidents
- Degraded performanceSep 4, 2026 · resolved in 17d 1h
- MaintenanceAug 9, 2026 · resolved in 1h 10m
Recent Klaviyo incidents
- Partial outageOct 29, 2026 · resolved in 2h 10m
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
Affected: Analytics
- Partial outageOct 17, 2026 · resolved in 4h 49m
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
Affected: Klaviyo App
Other email marketing platforms to consider
- Drip · #1 · 100% uptime
- MailerLite · #2 · 100% uptime
- Omnisend · #3 · 100% uptime
- AWeber · #4 · 100% uptime
See the full most reliable email marketing platforms ranking →