Customer.io vs Klaviyo
Behavioral lifecycle automation for SaaS versus event-rich ecommerce automation.
What matters for SaaS product teams
A SaaS product sends on behalf of its customers, so the deciding factors are tenant isolation, whether suppressions can be scoped rather than global, and whether support can answer why one specific account did not receive one specific email. Lifecycle automation and transactional sending usually need to coexist.
| Priority | Customer.io | Klaviyo |
|---|---|---|
| Multi-tenant | Yes | No |
| Event stream | Yes | Yes |
| Suppressions API | Yes | Yes |
| Operating since | 2012 | 2012 |
| Scheduling | Yes | Yes |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Deliverability | Good; reputation managed at the workspace level with optional dedicated IPs. | Solid for ecommerce traffic. |
| Webhooks | Yes | Yes |
| Starts at | $100/mo (Essentials) | $45/mo for 5,000 emails |
For a multi-tenant SaaS product running trial expiry notices, dunning, onboarding sequences, and per-tenant transactional mail, Customer.io takes every priority that separates them here (multi-tenant support), while Klaviyo matches it on the rest. On entry price, Customer.io offers $100/mo (Essentials) against $45/mo for 5,000 emails from Klaviyo. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Customer.io | Klaviyo |
|---|---|---|
| Multi-tenant | Yes | No |
| Deliverability | Good; reputation managed at the workspace level with optional dedicated IPs. | Solid for ecommerce traffic. |
| Webhooks | Yes | Yes |
| Starts at | $100/mo (Essentials) | $45/mo for 5,000 emails |
| Tagline | Behavior-driven lifecycle messaging. | Ecommerce-focused marketing automation. |
| Free tier | No permanent free tier; trial only | 500 emails to 250 contacts |
| Pricing model | subscriber-based | subscriber-based |
| API | Yes | Yes |
| SMTP | No | No |
| SDKs | node, python, go, ruby, php, java | node, python, php, ruby |
| Templates | rich | rich |
| React Email | No | No |
| Inbound | No | No |
| Idempotency | No | No |
| Dedicated IP | Yes | Yes |
| DX score | 7/10 | 6/10 |
| Best for | B2B SaaS teams running complex onboarding and lifecycle programs. | Shopify and ecommerce teams. |
Customer.io
- ›Best-in-class behavioral targeting
- ›Strong workflow editor
- ›Multi-channel
- ›Expensive starting price
- ›Overkill for pure transactional
- ›Pricing scales with users
Klaviyo
- ›Ecommerce integrations are deep
- ›Predictive analytics
- ›Weak for non-ecommerce use cases
- ›Pricing climbs fast with contact growth