Sendgrid vs Customer.io Comparison (2026)

Compare Sendgrid vs Customer.io email services. In-depth analysis of features, pricing, security, privacy, and storage to find the best email provider for your needs.

Forward Email Team
Written by
Forward Email TeamVerified
Published
4/1/26
Time to read
Less than 5 minutes
We recommend Forward Email as the best alternative to Sendgrid. We also support webmail: https://mail.forwardemail.net

Email Service Comparison

20 facts in comparison
Sendgridvs.Customer.io

Sendgrid

Get your emails to the inbox—where they belong
"Get your emails to the inbox—where they belong"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

Customer.io

Send messages people actually want to receive using real-time customer data
"Send messages people actually want to receive using real-time customer data"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$19.95/moPricing$100/mo
No Sendgrid does not support storageStorageNo Customer.io does not support storage
30 MBAttachments2 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
YesSMTPYes
NoIMAPNo
NoPOP3No
YesAPIYes
NoE2EE No
NoOpenPGP No
NoWKD No

Email Service Screenshots

Closed-source

Sendgrid

Sendgrid is a closed-source email service. Their official description reads: Get your emails to the inbox—where they belong

Sendgrid is a closed-source email service.
Photograph by Forward Email
Visit Website
Closed-source

Customer.io

Customer.io is a closed-source email service. Their website says: Send messages people actually want to receive using real-time customer data

Customer.io is a closed-source email service.
Photo by Forward Email
Visit Website

Compare Sendgrid with 78 email services