Customer.io vs Mailjet
Customer.io and Mailjet are both popular choices in the email marketing platform space. Mailjet starts at $17/mo versus $100/mo for Customer.io. Mailjet offers a free plan (6,000 emails/month (200/day), 1,000 contacts), while Customer.io does not.
Quick Verdict
Customer.io wins on deliverability, rating, integrations.
Mailjet wins on price, free tier.
Best for most users: Customer.io (product led saas companies with event driven messaging needs).
Customer.io
Behavioral messaging platform for product-led SaaS and tech companies
Customer.io is a behavioral messaging platform built for product-led SaaS companies that need to trigger automated emails, SMS, push notifications, and in-app messages based on real-time user events. Its visual workflow builder and Liquid templating provide deep personalization, while the built-in Data Pipelines act as a lightweight CDP. Trusted by 8,000+ companies including Notion and Segment, it starts at $100/month for 5,000 profiles.
Mailjet
Collaborative email platform for teams with powerful API
Mailjet is a French-founded email platform (now owned by Sinch) that uniquely combines transactional and marketing email under one roof with real-time team collaboration. Its volume-based pricing with unlimited contacts makes it particularly cost-effective for businesses with large subscriber lists but moderate sending frequency. With strong GDPR compliance baked into its European DNA and a flexible API, it bridges the gap between developer-focused tools and marketer-friendly platforms.
Feature Comparison
| Feature | Customer.io | Mailjet |
|---|---|---|
| Rating | 4.4/5 | 4/5 |
| Starting Price | $100/mo | $17/mo |
| Free Plan | No free plan | 6,000 emails/month (200/day), 1,000 contacts |
| Founded | 2012 | 2010 |
| Email Templates | 30 | 70 |
| Integrations | 150 | 110 |
| Deliverability Rate | 96% | 88% |
| Marketing Automation | ✓ | ✓ |
| A/B Testing | ✓ | ✓ |
| Landing Pages | ✕ | ✕ |
| Segmentation | ✓ | ✓ |
| Drag & Drop Editor | ✓ | ✓ |
| SMS Marketing | ✓ | ✓ |
| Ecommerce Features | ✕ | ✕ |
| API Access | ✓ | ✓ |
| Multi-Language | ✓ | ✓ |
| Web Push Notifications | ✓ | ✕ |
| Live Chat | ✕ | ✕ |
| Advanced Analytics | ✓ | ✓ |
Customer.io: Pros & Cons
Pros
- +Powerful visual workflow builder with real-time event-based triggers for behavioral automation
- +Omnichannel messaging across email, SMS, push notifications, in-app, and webhooks in one platform
- +Built-in Data Pipelines that serve as a lightweight CDP, unifying web, mobile, and backend data
- +Segment builder is intuitive enough for marketers without requiring dedicated engineering support
- +Startup Program offers up to 12 months free for qualifying early-stage companies
Cons
- −Essentials plan starts at $100/month for only 5,000 profiles — expensive for small teams
- −Steep learning curve for non-technical users, especially with Liquid templating syntax
- −Pricing scales aggressively past 10K profiles with significant jumps between plan tiers
- −Template editor feels restrictive for highly custom-coded email layouts
- −Searching for past messages and editing templates can be unintuitive and slow
Mailjet: Pros & Cons
Pros
- +Real-time collaborative email editing lets multiple team members work on the same campaign simultaneously with live comments
- +Volume-based pricing with unlimited contacts means large lists stay affordable — one user grew from 0 to 50,000 subscribers affordably
- +Strong GDPR compliance built into the platform with EU data hosting, as a French-founded company under European regulations
- +RESTful API with SMTP relay supports both transactional and marketing email from a single platform
- +Deliverability rated 88% by EmailToolTester (above 83.1% industry average) with built-in list validation powered by Mailgun
Cons
- −Automation builder covers basics but lacks depth — triggers based on opens/clicks are tricky to configure and abandoned cart requires Zapier
- −No built-in landing page builder, forcing users to rely on third-party tools for lead capture
- −Many of the 110 integrations route through Zapier rather than being native direct connections
- −Migration from other ESPs is largely manual with limited import assistance for contacts, templates, and automations
- −Customer support response times are frequently criticized, with some serious technical issues going unresolved for extended periods
The Verdict
Customer.io edges ahead with a 4.4/5 rating compared to Mailjet's 4/5. The gap comes mainly from deliverability (4.4 vs 3.5) and ease of use (4.7 vs 4.2). On deliverability, Customer.io reports 96% compared to 88% for Mailjet — a meaningful difference if inbox placement is critical for your campaigns.
| Criterion | Weight | Customer.io | Mailjet |
|---|---|---|---|
| Starting Price | 30% | $100/mo | $17/mo |
| Deliverability | 25% | 96% | 88% |
| Rating | 25% | 4.4/5 | 4/5 |
| Integrations | 10% | 150 | 110 |
| Free Tier | 10% | No | Yes |
Weights determine how much each criterion counts toward the final score. See full methodology
Choose Customer.io if…
- + You're a product led saas companies with event driven messaging needs
- + You're a technical marketing teams that want advanced automation with liquid logic
- + Powerful visual workflow builder with real-time event-based triggers for behavioral automation
Choose Mailjet if…
- + You want lower starting costs ($17/mo)
- + You need a free plan to get started
- + You're a marketing teams needing real time email collaboration
- + You're a european businesses requiring gdpr compliant email