Kit (ConvertKit) vs Customer.io
Kit (ConvertKit) and Customer.io are both popular choices in the email marketing platform space. Kit (ConvertKit) is the more affordable option at $33/mo — that's $67 less per month than Customer.io's $100/mo entry point. Kit (ConvertKit) offers a free plan (10,000 subscribers), while Customer.io does not. Kit (ConvertKit) stands out with landing pages and ecommerce integrations, while Customer.io offers SMS marketing and a drag-and-drop editor.
Quick Verdict
Kit (ConvertKit) wins on price, deliverability, rating, free tier.
Customer.io wins on integrations.
Best for most users: Kit (ConvertKit) (bloggers).
Kit (ConvertKit)
Email marketing built for creators
Kit (formerly ConvertKit) is purpose-built for online creators including bloggers, podcasters, YouTubers, and course creators. It emphasizes simplicity and deliverability over complex design features, making it ideal for text-based newsletters and automated sequences.
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.
Feature Comparison
| Feature | Kit (ConvertKit) | Customer.io |
|---|---|---|
| Rating | 4.6/5 | 4.4/5 |
| Starting Price | $33/mo | $100/mo |
| Free Plan | 10,000 subscribers | No free plan |
| Founded | 2013 | 2012 |
| Email Templates | 50 | 30 |
| Integrations | 90 | 150 |
| Deliverability Rate | 98.2% | 96% |
| 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 | ✓ | ✓ |
Kit (ConvertKit): Pros & Cons
Pros
- +Excellent creator ecosystem with built-in monetization
- +Intuitive visual automation builder
- +Generous free plan up to 10,000 subscribers
- +Strong deliverability rates
- +Creator-focused features like tip jars and paid newsletters
Cons
- −Limited email template design options
- −Gets expensive at higher subscriber counts
- −No SMS marketing capabilities
- −Basic reporting compared to competitors
- −No drag-and-drop email editor
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
The Verdict
Kit (ConvertKit) and Customer.io are closely matched — both score within 0.2 points of each other in our overall rating. Your decision should come down to specific needs rather than overall quality. On deliverability, Kit (ConvertKit) reports 98.2% compared to 96% for Customer.io — a meaningful difference if inbox placement is critical for your campaigns.
| Criterion | Weight | Kit (ConvertKit) | Customer.io |
|---|---|---|---|
| Starting Price | 30% | $33/mo | $100/mo |
| Deliverability | 25% | 98.2% | 96% |
| Rating | 25% | 4.6/5 | 4.4/5 |
| Integrations | 10% | 90 | 150 |
| Free Tier | 10% | Yes | No |
Weights determine how much each criterion counts toward the final score. See full methodology
Choose Kit (ConvertKit) if…
- + You want lower starting costs ($33/mo)
- + You need a free plan to get started
- + You need ecommerce integrations
- + You need built-in landing pages
Choose Customer.io if…
- + You need SMS marketing
- + 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