Customer.io vs GMass

See how their public offers line up before you choose your own position. Prices stay in the currency, billing schedule, and charged unit each vendor publishes.

Customer.io

See full pricing history

USD · US · source: customer.io

Plan	Pricing	Charged by	Offer type
Essentials	USD 100 monthly Starts at $100/month billed monthly	Flat · per month	Standalone · Starting at
Premium Highlighted	USD 1000 / month with annual commitment Starts at $1,000/month billed yearly	Flat · per month	Standalone · Starting at

GMass

See full pricing history

EUR · US · source: www.gmass.co

Plan	Pricing	Charged by	Offer type
Standard — Individual Monthly	EUR 26 monthly · EUR 17 / month with annual commitment € 17 / month €215 paid annually	Flat · month	Standalone · Fixed
Premium — Individual Monthly Highlighted	EUR 35 monthly · EUR 25 / month with annual commitment € 25 / month €305 paid annually	Flat · month	Standalone · Fixed

What each plan includes

Feature names follow each vendor’s own pricing page, so verify the wording before treating them as exact equivalents.

Customer.io

Essentials

Plan card Profiles: 5,000

Included
Plan card Emails: 1 million/month

Included
Plan card Visual workflow builder: Included

Premium

Plan card Unlimited workspaces: Included
Plan card Advanced governance: Included
Plan card Dedicated implementation support: Included

GMass

Standard — Individual Monthly

Highlights Works inside Gmail: ✓

Included
Highlights Send unlimited emails!*: ✓

Included
Highlights Unlimited contacts: ✓

Included
Highlights Unlimited campaigns: ✓

Included
Highlights Mail merge personalization: ✓

Included
Highlights Free email address verification: ✓

Included
Highlights Custom tracking links w/SSL: ✓

Included
Highlights Spam Solver: ✓

Included
Highlights Sequences and follow-ups: ✓

Included
Highlights API access (+Zapier): ×

Excluded
Highlights A/B testing: ×

Excluded
Highlights Triggered Emails: ×

Excluded
Highlights Inbox Rotation (MultiSend): ×

Excluded
Highlights High-priority support: ×

Excluded
Highlights Email support: ✓

Included
Highlights Hundreds of other features: ✓

Included

Premium — Individual Monthly

Highlights Works inside Gmail: ✓

Included
Highlights Send unlimited emails!*: ✓

Included
Highlights Unlimited contacts: ✓

Included
Highlights Unlimited campaigns: ✓

Included
Highlights Mail merge personalization: ✓

Included
Highlights Free email address verification: ✓

Included
Highlights Custom tracking links w/SSL: ✓

Included
Highlights Spam Solver: ✓

Included
Highlights Sequences and follow-ups: ✓

Included
Highlights API access (+Zapier): ✓

Included
Highlights A/B testing: ✓

Included
Highlights Triggered Emails: ✓

Included
Highlights Inbox Rotation (MultiSend): ✓

Included
Highlights High-priority support: ×

Excluded
Highlights Email support: ✓

Included
Highlights Hundreds of other features: ✓

Included

How their prices changed

Each dated row shows the public prices observed when that vendor’s pricing page changed.

Customer.io

August 27, 2026 Source
- Essentials: USD 100 monthly
- Premium: USD 1000 / month with annual commitment

GMass

August 27, 2026 Source
- Standard — Individual Monthly: EUR 26 monthly · EUR 17 / month with annual commitment
- Premium — Individual Monthly: EUR 35 monthly · EUR 25 / month with annual commitment