Customer.ioCustomer Engagement Platform For Better Outcomes
vs
MailgunTransactional Email API Service For Developers
Comparison · Email Marketing · weekly run Nov 2
Customer.io vs Mailgun
Which one do AI engines recommend, and how do they differ on price, fit and features?
The short answer
Customer.io is the stronger AI pick in Email Marketing: it has a visibility score of 6.2 versus 0.9 for Mailgun.
Choose Customer.io if…
- You want the brand AI engines rank higher (6.2 vs 0.9)
- AI answers describe it more positively (34% vs 0% positive)
- You need GDPR or CCPA or ISO 27001 or HIPAA coverage
- Strong behavioral and event-driven automation
Choose Mailgun if…
- You want a free plan to start
- You need ISO/IEC 27001 or ISO 27701 or GDPR compliant or HIPAA compliant or PCI-compliant SAQ-A merchant coverage
- recommended for sending larger volumes programmatically
AI visibility side by side
Latest weekly run · Nov 2
| Metric | Customer.io | Mailgun |
|---|---|---|
| Visibility score | 6.2% | 0.9% |
| Change vs last week | New | New |
| Rank in Email Marketing | #16 | #36 |
| Share of voice | 1.7% | 0.2% |
| Mentions this run | 10 | 1 |
| Positive in AI answers | 34% | 0% |
The stronger value in each row is marked with a ✓.
Visibility score trend
Weekly runs over the last 60 days
Customer.io 0pp · Mailgun 0pp over 0 weekly runs.
Engine by engine
Customer.io leads on 2 of 3 engines
ChatGPT
AI Mode
Perplexity
Customer.ioMailgun
Head to head in AI answers
0 engine answers name both brands
0Customer.io ranked higher
0Mailgun ranked higher
Features, pricing & fit
| Dimension | Customer.io | Mailgun |
|---|---|---|
| Pricing model | Usage-based | Usage-based |
| Entry price | $100 / mo | Free; paid from $15 / mo |
| Free plan | No | Yes |
| Deployment | Cloud-hosted, with US and EU data centers | Cloud, hosted in US and EU regions |
| Compliance | GDPR, CCPA, ISO 27001, SOC 2 Type II, HIPAA | SOC 2 Type II, ISO/IEC 27001, ISO 27701, GDPR compliant, HIPAA compliant, PCI-compliant SAQ-A merchant |
| Support | Email and chat support, Documentation and community support, Dedicated Customer Success Manager on Enterprise | Knowledge Center, Documentation, Ticket support, Chat support on higher plans |
| Founded | 2012 | 2010 |
| Headquarters | Portland, Oregon, USA | — |
| Employees | 201–500 | 201–500 |
| Funding | Series A led by Spectrum Equity | Growth investment (Thoma Bravo) · $51M raised |
| Best for | Teams getting started with data-driven messaging, and teams scaling across channels with custom workflows. | Developers and engineering teams that need to send transactional and marketing email through an API |
Plans side by side
Customer.io
Essentials$100month, billed monthly (starts at, 5k profiles)
Premium$1,000month, billed yearly (starts at)
EnterpriseCustomcontact sales
Mailgun
Free$0month
Basic$15month (10,000 emails included)
Foundation$35month (50,000 emails included)
Scale$90month (100,000 emails included)
EnterpriseCustomcustom
Pros and cons
Themes from the AI answers that mention each brand
Customer.io
- Strong behavioral and event-driven automation
- Well suited to product-led SaaS companies
- Supports onboarding, activation and retention messaging
- Frequently shortlisted as a top marketing automation choice
Mailgun
- recommended for sending larger volumes programmatically
Data collected ·ChatGPT, Perplexity, Google AI Mode·coverage 100%·next run
Cite as: SlateIndex, “Customer.io vs Mailgun”, https://slateindex.ai/compare/customer-io-vs-mailgun, data of Nov 2, 2026. Licence: CC BY 4.0.