Customer.io vs Mailjet
Customer.io and Mailjet are both popular choices in the email marketing platform space. Customer.io starts at $100/mo, while Mailjet starts at $9/mo. Their pricing is not measured the same way, so we don't rank them on price. Mailjet offers a free plan (6,000 emails/month (200/day), 1,000 contacts), while Customer.io does not. Mailjet has the edge with landing pages.
Quick Verdict
Customer.io wins on deliverability, rating, integrations.
Mailjet wins on 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 | $9/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 | Yes | Yes |
| A/B Testing | Yes | Yes |
| Landing Pages | No | Yes |
| Segmentation | Yes | Yes |
| Drag & Drop Editor | Yes | Yes |
| SMS Marketing | Yes | Yes |
| Ecommerce Features | No | No |
| API Access | Yes | Yes |
| Multi-Language | Yes | Yes |
| Web Push Notifications | Yes | No |
| Live Chat | No | No |
| Advanced Analytics | Yes | Yes |
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 | $9/mo |
| Deliverability | 25% | 96% Winner | 88% |
| Rating | 25% | 4.4/5 Winner | 4/5 |
| Integrations | 10% | 150 Winner | 110 |
| Free Tier | 10% | No | Yes Winner |
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 need a free plan to get started
- + You need built-in landing pages
- + You're a marketing teams needing real time email collaboration
- + You're a european businesses requiring gdpr compliant email