ESPB
Latest
Feb 18, 2026Plunk: Dashboard Analytics DelayedFeb 15, 2026The State of Email Delivery in 2026Feb 8, 2026Mailgun: EU Region Delivery DelaysFeb 3, 2026Loops: API Documentation UnavailableFeb 1, 2026Q1 2026 ESP Performance ReportJan 28, 2026API Latency Comparison: Which ESP Responds Fastest?Jan 20, 2026Transactional Email Showdown: Postmark vs Resend vs BrewFeb 18, 2026Plunk: Dashboard Analytics DelayedFeb 15, 2026The State of Email Delivery in 2026Feb 8, 2026Mailgun: EU Region Delivery DelaysFeb 3, 2026Loops: API Documentation UnavailableFeb 1, 2026Q1 2026 ESP Performance ReportJan 28, 2026API Latency Comparison: Which ESP Responds Fastest?Jan 20, 2026Transactional Email Showdown: Postmark vs Resend vs Brew

Customer.io

78

Automated messaging platform

marketing
Operational
Founded 2012
Visit Website

Customer.io is a powerful marketing automation platform that goes beyond email to include SMS, push notifications, and in-app messaging. Its visual workflow builder and robust segmentation make it popular for complex customer journeys.

Speed
76
Reliability
79
Deliverability
78
Developer Experience
80
Value
77

Current Metrics

Updated just now
Delivery Speed (p50)250ms
Delivery Speed (p95)580ms
Delivery Speed (p99)870ms
Delivery Speed (avg)310ms
API Latency (p50)62ms
API Latency (p95)180ms
API Latency (p99)310ms
API Latency (avg)82ms
Uptime (30d)99.89%
Deliverability95.2%
Bounce Rate3.0%
Throughput9,000/s

12-Month Trend

Overall Score
Delivery Speed (avg ms)
Uptime %
Deliverability %

Features

✓Visual workflow builder
✓Multi-channel messaging
✓Segmentation
✓A/B testing
✓Data warehousing
✓Webhook triggers
Pricing starts at $100/mo (5,000 profiles)

Incidents (2)

Segmentation Engine DegradationMajor
Customer.io·Dec 19, 2025·2h·Resolved

The audience segmentation engine experienced severe performance degradation, causing delayed campaign processing. Segments requiring complex conditions were most affected.

Mobile Push Notification DelaysMinor
Customer.io·Aug 5, 2025·35m·Resolved

Push notifications were experiencing delivery delays of 2-5 minutes. Email delivery was functioning normally.

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