Customer.io vs Klaviyo: Complete Comparison (2026)
An in-depth comparison of Customer.io and Klaviyo to help you choose the right tool for your business.
Last updated: November 2026
Customer.io
6.5/10
Customer.io is a behavior-driven messaging platform that lets product-led and tech companies automate email, push, in-app, SMS and WhatsApp messages based on user data.
Klaviyo
6.9/10
Klaviyo is an email, SMS and customer data platform for ecommerce brands, priced by active profiles and built around store data and automated flows.
Feature-by-Feature Comparison
| Feature | | |
|---|---|---|
| Scores | ||
| Overall Rating | 6.5/10 | 6.9/10 |
| Scalability | 8/10 | 8/10 |
| Ease of Use | 5/10 | 6/10 |
| Customization | 9/10 | 8/10 |
| Security | 8/10 | 7/10 |
| Support | 5/10 | 5/10 |
| Cost | 4/10 | 4/10 |
| Integration | 8/10 | 9/10 |
| Analytics | 5/10 | 9/10 |
| Pricing | ||
| Free plan | No | Yes |
| Cheapest paid plan | $100/mo Essentials | $20/mo Email |
| Estimated cost for 10 users | $100/mo Essentials | Free Free |
| Features | ||
| Landing Pages | ||
| Email Marketing | ||
| Segmentation | ||
| SMS Marketing | ||
| A/B Testing | Not listed | |
| E-commerce Features | Not listed | |
Customer.io vs Klaviyo cost by team size
Klaviyo costs less at every team size we checked.
| Team size | Customer.io | Klaviyo |
|---|---|---|
| 1 user | $100/moEssentials | FreeFree |
| 5 users | $100/moEssentials | FreeFree |
| 10 users | $100/moEssentials | FreeFree |
| 25 users | $100/moEssentials | FreeFree |
| 50 users | $100/moEssentials | FreeFree |
The plan that fits each team size, billed monthly, before add-ons and usage charges. Each cost opens that tool's pricing calculator for the team size.
Which One Should You Choose?
Why choose Customer.io
- Higher Customization score (9/10 vs 8/10)
- Higher Security score (8/10 vs 7/10)
- Better fit for startups (8/10 vs 6/10)
Why choose Klaviyo
- Has a free plan (Customer.io does not)
- Lower estimated cost for 10 users: Free vs $100/mo
- Higher Analytics score (9/10 vs 5/10)
- Higher Ease of Use score (6/10 vs 5/10)
- Better fit for e-commerce (10/10 vs 4/10)
Pros & Cons
Customer.io
Pros
- Its visual workflow builder supports branching, goals and loops, and it can coordinate email, push, in-app, SMS and WhatsApp in one flow.
- Segmentation can use custom events, attributes and inactivity windows, and a built-in CDP stores custom objects.
- Every plan includes API and webhook access, and reviewers say developers can connect it easily.
- It holds SOC 2 Type II and ISO 27001 certifications, supports HIPAA, offers SSO, and lets you choose US or EU data residency.
- Startups that have raised under $10M can get up to 12 months free.
Cons
- Every stored profile counts toward the bill, inactive ones included, so costs climb quickly as the contact list grows.
- Setup has a steep learning curve and usually needs a developer to implement event tracking.
- There are no native landing pages or signup forms.
- Reviewers say reporting is limited and often needs data exports.
- Chat support starts at Premium, and Essentials gets only email and community support.
Klaviyo
Pros
- Deep native integration with Shopify and other stores lets marketers segment on real purchase and browsing data.
- A free plan with 250 profiles and a 20 USD entry plan make it cheap to start.
- Since July 2026, SMS uses dollar-based plans with over 70 tiers, so gaps between plans are smaller and larger plans get lower per-message rates.
- A broad product suite covering reviews, helpdesk, personalization and AI agents can replace several separate tools.
Cons
- Billing by active profiles and uneven tier steps cause cost jumps, for example from 150 USD at 10,000 profiles to 350 USD at 15,000 on the Email plan.
- Many features, such as Reviews, Helpdesk, Personalization and Composer, are separately priced add-ons that raise the total bill.
- Free accounts get email support only for the first 60 days, and reviewers on G2 and Trustpilot report slow or hard-to-reach support.
- New users report a learning curve with segments, event triggers and flow logic.
Not sold on either?
Frequently Asked Questions
Klaviyo scores higher on our Marketing criteria: 6.9/10 against 6.5/10 for Customer.io. The largest gap is in Analytics: 5/10 for Customer.io and 9/10 for Klaviyo.
Klaviyo costs less for 10 users: free on its Free plan, against about $100/mo on its Essentials plan for Customer.io, billed monthly.
Klaviyo has a free plan; Customer.io does not list one.
Klaviyo is the better fit for e-commerce: we rate it 10/10 for them, against 4/10 for Customer.io.
Klaviyo has Landing Pages, which Customer.io lacks.
