Head-to-head
Customer.io vs GMass
Two leading email marketing tools, compared on pricing, features, and editorial fit. Updated for 2026.
At a glance
| Customer.io | GMass | |
|---|---|---|
| Tagline | Messaging that actually fits your data. | Send mass email, mail merge, and campaigns from inside Gmail |
| Pricing model | Paid | Paid |
| Starts at | $100/mo | $20/mo |
| Founded | 2012 | — |
| AI-native | ||
| Categories | Email Marketing, Automation | Sales Engagement, Email Marketing |
| Vendor claimed |
Quick take
Pick Customer.io if you need messaging that actually fits your data. Pick GMass if you need send mass email, mail merge, and campaigns from inside gmail.
Browse more
Customer.io alternatives →
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GMass alternatives →
Frequently asked
- Is Customer.io better than GMass?
- It depends on your use case. Customer.io is messaging that actually fits your data, while GMass is send mass email, mail merge, and campaigns from inside gmail. See the comparison above for which fits your team.
- What's the price difference between Customer.io and GMass?
- Customer.io starts at $100/mo. GMass starts at $20/mo.
- Can I migrate from Customer.io to GMass?
- Most tools in this category support data import via CSV. For complex migrations, both vendors offer onboarding assistance on higher-tier plans.