Best for
Best for product-led SaaS teams that trigger lifecycle messaging from event data and want the whole platform available over an API.
- Small and mid-sized
- Enterprise
Email Marketing Comparison
Customer.io vs. Mailjet
At a glance
At a glance
Best for
Best for teams and developers that want one platform for both marketing campaigns and transactional email, priced by send volume.
- Freelancers
- Small and mid-sized
- Enterprise
Cataleo does not name a winner. Both statements come from the vendors themselves.
Full Comparison
| Criterion | Customer.io | Mailjet |
|---|---|---|
| Starting price | From $100 / month Essentials, billed monthly, for 5,000 profiles and 1 million emails a month. Premium starts at $1,000 a month and is billed yearly; Enterprise is quoted. Extra usage costs $0.009 per profile, $0.12 per 1,000 emails and $10 per 100,000 AI credits. | lower value From $9 / month Starter plan; priced by monthly email volume. A free plan is available. |
| Free trial | Startup Program gives early-stage companies that have raised under $10M a full year free | Free plan with 6,000 emails per month (200 per day) |
| API | Yes, the Journeys UI API and CDP Data Pipelines API, plus a CLI, webhooks, mobile SDKs and an official MCP server | Yes, a Send API and SMTP relay on all paid plans |
| Hosting | Cloud (SaaS), with US and EU endpoints | Cloud (SaaS) |
| Made in | United States | Not stated |
| Campaign types | Yes, email, SMS, push, in-app messages, WhatsApp, LINE, webhooks and Slack, plus transactional messages | Yes, marketing campaigns and newsletters plus transactional email, with landing pages on Premium |
| Automation and journeys | Yes, a visual workflow builder with branching logic, triggered by segment, event, form, relationship, date or webhook | Yes, automations on the Premium plan |
| Segmentation and personalisation | Yes, Audiences segments on customer profiles, events, account relationships and real-time data | Yes, segmentation from the Essential plan, with dynamic content on Premium |
| Templates and editor | Yes, Design Studio for creating messages at scale | Yes, an advanced drag-and-drop editor on every plan |
| Deliverability and testing | A/B and multivariate testing, conversion tracking, send-time optimisation and email content analysis on every plan; managed deliverability from the Premium plan | Yes, A/B testing on Premium, with a dedicated IP available on higher-volume plans |
| Ecommerce and CRM data | Yes, CDP Data Pipelines unify customer data and apps, with object types alongside people for accounts and other non-person records | Through connectors rather than a built-in store sync: Mailjet ships its own plugins for WordPress with WooCommerce and for PrestaShop, while the other ecommerce and CRM entries in its integrations directory, among them Shopify, HubSpot and Salesforce, are connected through Zapier or another iPaaS partner |
| Integrations and API | Yes, the Journeys UI API and CDP Data Pipelines API, plus a CLI, webhooks, mobile SDKs for iOS, Android, React Native, Flutter and Expo, and an official MCP server | Yes, a Send API and SMTP relay on all paid plans |
| AI features | Yes | Yes |
| MCP-ready | Yes | Yes |
| Deployment | Cloud (SaaS), Browser-based | Cloud (SaaS), Browser-based |
| Support | Email helpdesk, Chat, Community forum | Email helpdesk, Phone, Chat |
| Onboarding | Documentation and knowledge base, Guided onboarding | more entries Documentation and knowledge base, Video tutorials, Guided onboarding |
| Company size | Small and mid-sized, Enterprise | more entries Freelancers, Small and mid-sized, Enterprise |
| Integrations | Not stated | WordPress, WooCommerce, PrestaShop, Drupal, Joomla, Squarespace, Webflow, Shopify, BigCommerce, Stripe, PayPal, Salesforce, HubSpot, Pipedrive, Zoho, Microsoft Dynamics CRM, Segment, Zapier, Make, n8n, Slack, Zendesk, Intercom, Google Sheets, Airtable, Typeform, Sinch Engage |
Add a tool
Adds a column to the table, from the tools in this category.
Row where the values differ The small markers point at the lower number, the longer list or the stated feature. They describe the data, they are not a verdict.
The short version
Key Differences
- Starting price Customer.io From $100 / month Mailjet From $9 / month
- Free trial Customer.io Startup Program gives early-stage companies that have raised under $10M a full year free Mailjet Free plan with 6,000 emails per month (200 per day)
- Company size Customer.io Small and mid-sized, Enterprise Mailjet Freelancers, Small and mid-sized, Enterprise
- Hosting Customer.io Cloud (SaaS), with US and EU endpoints Mailjet Cloud (SaaS)
- Support Customer.io Email helpdesk, Chat, Community forum Mailjet Email helpdesk, Phone, Chat
Every line is one datapoint from the table above, picked automatically. Nothing here is written text.
The trade-offs
Strengths and Limitations
Customer.io
Strengths
- Journeys triggered by product events, forms, relationships, dates or webhooks
- Official MCP server exposing the full Journeys UI and CDP Data Pipelines APIs, on US and EU endpoints
- LLM actions inside a workflow generate data and personalise content at send time
- Startup Program gives early-stage companies a full year free
Limitations
- Only Essentials publishes its volumes; Premium names a starting figure but quotes profiles and emails individually
- Billing counts objects as well as people towards the profile total
- Object types are capped per plan, at two on Essentials and ten on Premium
- Daily Routines, premium chat support and HIPAA compliance start at the Premium plan
Mailjet
Strengths
- Priced by email volume, with unlimited contacts on the Essential and Premium plans
- Advanced drag-and-drop editor on every plan, including the free tier
- Send API and SMTP relay for transactional email on all paid plans
- Free plan with 6,000 emails per month
Limitations
- Automations, A/B testing and dynamic content are reserved for the Premium plan
- The Free and Starter plans cap contacts at 1,000 and 2,000
Plans
Pricing
Customer.io
- Essentials $100 Per month, billed monthly. 5,000 profiles (people and objects), 1 million emails a month, 2 object types, 2 workspaces, email and community support, basic data integrations.
- Premium $1,000 Per month, billed yearly, as a starting figure. Custom profile and email volumes, 10 object types, elevated AI Agent limits with custom skills, Daily Routines, premium chat and email support, 90-day onboarding support, premium data integrations and HIPAA compliance.
- Enterprise Not stated Quoted. Dedicated infrastructure and hardware, custom AI Agent limits, priority technical support, migration support, a dedicated Customer Success Manager and Technical Implementation Specialist, a shared Slack channel, audit logging and data governance.
Mailjet
- Free $0 / month 6,000 emails per month (200 per day), up to 1,000 contacts, with the advanced drag-and-drop editor.
- Starter From $9 / month 8,000 emails per month, up to 2,000 contacts, with online support.
- Essential From $17 / month 15,000 emails per month, unlimited contacts, segmentation and no daily send limit.
- Premium From $27 / month Adds automations, A/B testing, dynamic content, landing pages and up to 20 subaccounts, plus priority support, with phone and chat support from 50,000 emails a month.
- Custom Not stated Custom enterprise plans for high-volume senders, with a dedicated technical account manager, unlimited subaccounts, phone and chat support and guided onboarding, training and consulting.
What users say
Review Scores · opens after launch
Customer.io
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Mailjet
- Ease of use
- Not rated yet
- User interface
- Not rated yet
- Onboarding
- Not rated yet
- Support and service
- Not rated yet
- Value for money
- Not rated yet
- Features
- Not rated yet
No reviews yet. Be the first to review this tool. Every review is checked for fairness before it appears, and the vendor cannot have one removed.
Where this comes from
Where this comes from
Customer.io https://customer.io · checked against the official source on 2026-09-03
Mailjet https://www.mailjet.com · checked against the official source on 2026-08-21
This table lists factual criteria taken from information the vendors publish themselves. For how we put it together, see the methodology.