Head-to-head
Customer.io vs MailKing
Two leading email marketing tools, compared on pricing, features, and editorial fit. Updated for 2026.
At a glance
| Customer.io | MailKing | |
|---|---|---|
| Tagline | Messaging that actually fits your data. | Send email campaigns and mass mail merges directly from Gmail |
| Pricing model | Paid | Freemium |
| Starts at | $100/mo | $14.99/mo |
| Founded | 2012 | — |
| AI-native | ||
| Categories | Email Marketing, Automation | Forms & Surveys, Email Marketing |
| Vendor claimed |
Quick take
Pick Customer.io if you need messaging that actually fits your data. Pick MailKing if you need send email campaigns and mass mail merges directly from gmail.
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Frequently asked
- Is Customer.io better than MailKing?
- It depends on your use case. Customer.io is messaging that actually fits your data, while MailKing is send email campaigns and mass mail merges directly from gmail. See the comparison above for which fits your team.
- What's the price difference between Customer.io and MailKing?
- Customer.io starts at $100/mo. MailKing starts at $14.99/mo.
- Can I migrate from Customer.io to MailKing?
- Most tools in this category support data import via CSV. For complex migrations, both vendors offer onboarding assistance on higher-tier plans.