Email Marketing Platforms · reliability comparison
Klaviyo vs Mailchimp: which is more reliable? (2026)
Klaviyo is more reliable than Mailchimp, scoring 62.2 vs 55.1 out of 100. Over the last 90 days Klaviyo reported 13 incidents and Mailchimp reported 7, with effective uptime of 99.26% and 99.28% respectively. Klaviyo resolves incidents faster on average (3h 39m).
Data updated Nov 1, 2026 · How we score
| Metric | Klaviyo | Mailchimp |
|---|---|---|
| Reliability score | 62.2 | 55.1 |
| Rank (email marketing platforms) | #11 | #13 |
| Uptime (90 days) | 99.26% | 99.28% |
| Incidents (90 days) | 13 | 7 |
| Partial / major outages | 5 | 0 |
| Avg time to resolve | 3h 39m | 1d 1h |
| Outages we detected | 0 | 0 |
| Transparency score | 100/100 | 100/100 |
Where Klaviyo and Mailchimp differ
- Klaviyo reported 86% more incidents than Mailchimp over the last 90 days (13 vs 7).
- Klaviyo had 5 partial or major outages, compared with 0 for Mailchimp.
- Klaviyo fixes problems faster: 3h 39m on average, against 1d 1h for Mailchimp (7.1× quicker).
- Klaviyo's longest outage on record lasted 2d 1h (May 5, 2026); Mailchimp's lasted 3d (Oct 9, 2026).
90-day uptime
Klaviyo
Mailchimp
- No incidents
- Degraded
- Partial outage
- Major outage
- No data
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
Recent Mailchimp incidents
- Degraded performanceOct 29, 2026 · resolved (duration not published)
Access Issues and Errors Across Mailchimp
Affected: Access Issues and Errors Across Mailchimp
- Degraded performanceOct 27, 2026 · resolved in 1d 2h
Access Issues and Errors Across Mailchimp
Affected: Access Issues and Errors Across Mailchimp
- Degraded performanceOct 9, 2026 · resolved in 10d 12h
Cropped Images Disappearing in Campaigns
Affected: Cropped Images Disappearing in Campaigns
- Degraded performanceSep 11, 2026 · resolved in 2h 37m
Delayed updates to All Contacts table
Affected: Delayed updates to All Contacts table
- Degraded performanceAug 13, 2026 · resolved (duration not published)
Campaign links resulting in "500" errors.
Affected: Campaign links resulting in "500" errors.
- Degraded performanceAug 4, 2026 · resolved (duration not published)
Affected: Campaign Click Tracking Issue
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 →