Customer IO
Automate powerful behavioral messages for web & mobile apps
Folderly
Make the inbox your only destination folder
Updated February 2026
| Customer IO | Folderly | |
|---|---|---|
| Rating | 4.6★ | 5.0★ |
| Reviews | 24 | 48 |
| Pros | 10 | 17 |
| FactScore™ | 64.7 | 84.5 |
FactScore™ Comparison
FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.
Pros & Cons
Only in Customer IO — Pros
Behavioral messaging Personalized communication Automation capabilities Free startup plan Segmentation User engagement Email builder Multi-channel messaging Workflow customizationBoth tools — Pros
Customer supportOnly in Folderly — Pros
Email deliverability User-friendly interface Spam prevention Comprehensive solution Robust features Email outreach optimization Email spam words checker DNS settings management Increased open rates AI-driven approach Best practices recommendations Blacklist monitoring Spam trigger detection Email infrastructure analysis Real-time monitoring Simple setupOnly in Customer IO — Cons
Complex interface Email editor issues Inflexible journeys Limited CMS features Slow UIBoth tools — Cons
—Only in Folderly — Cons
—Details
| Customer IO | Folderly | |
|---|---|---|
| Categories | Email marketing, Marketing automation platforms, Customer loyalty platforms | Email marketing, Marketing automation platforms, Safety and Privacy platforms, AI Infrastructure Tools |
| Platforms | Web | Web |
| Became Popular | January 29, 2014 | November 26, 2020 |
| Website | customer.io | folderly.com |
Who Should Pick Which?
Choose Customer IO if...
- Behavioral messaging
- Personalized communication
- Automation capabilities
Choose Folderly if...
- Email deliverability
- User-friendly interface
- Spam prevention
With a FactScore™ of 64.7 vs 84.5, Folderly leads in community reception. Customer IO uniquely offers Behavioral messaging and Personalized communication, while Folderly stands out for Email deliverability and User-friendly interface.
What Users Say
Customer IO
We made the switch to Customer.io after trying out Loops and Userlist, and it’s been a great decision. It’s powerful enough to handle all our SaaS communication needs, yet still easy to use. It wor...
Our new email campaign provider with a user-friendly interface, clear visual logic for campaign triggers, and lots of customization. The level of flexibility has encouraged us to be more creative a...
Customer IO stands out for its powerful automation capabilities and behavioral messaging tools. It allows us to create highly personalized communication workflows, improving engagement and retentio...
Folderly
I think Folderly is truly changing the game in the email deliverability industry, leaving warmup solutions in the dust 😍 It's more than diagnosing and applying a "patch." This solution fixes deliv...
I've been here since the early days of Folderly, witnessing its growth and development. With our ever-evolving platform, we're now proud to have helped hundreds of clients! Our Customer Success tea...
Proper email deliverability prepares and maintains the entire email infrastructure. Google Startups Fund backs Folderly to create a comprehensive deliverability solution. This includes managing dom...
Frequently Asked Questions
Which is better, Customer IO or Folderly?
Based on FactScore™, Folderly leads with a score of 84.5 vs 64.7. Folderly has a higher rating of 5.0★ compared to 4.6★.
What are the pros of Customer IO compared to Folderly?
Customer IO uniquely offers: Behavioral messaging, Personalized communication, Automation capabilities, Free startup plan, Segmentation.
What are the pros of Folderly compared to Customer IO?
Folderly uniquely offers: Email deliverability, User-friendly interface, Spam prevention, Comprehensive solution, Robust features.
Is Customer IO better rated than Folderly?
Customer IO is rated 4.6★ from 24 reviews. Folderly is rated 5.0★ from 48 reviews.
What is the FactScore™ of Customer IO and Folderly?
FactScore™ weighs rating and review volume together. Customer IO scores 64.7 and Folderly scores 84.5.
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