Klaviyo vs MailerSend

Klaviyo and MailerSend (Email service that delivers) both appear on the Smoower Developer Ecosystem Index.

Klaviyo (rank #237) holds a narrow lead over MailerSend (rank #401) on the overall Smoower ecosystem score (48 vs 41). The gap of 7 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), Klaviyo is slightly ahead of MailerSend. On education (docs, guides and learning material for developers), MailerSend is clearly ahead of Klaviyo. On community (issue response, PR reviews and discussion health), Klaviyo is ahead of MailerSend. On reach (how visible the ecosystem is beyond its own repos), Klaviyo is ahead of MailerSend. On momentum (release cadence and how fast the ecosystem moves), Klaviyo is slightly ahead of MailerSend.

Klaviyo carries 573 GitHub stars across 117 public repos, with 23 repositories active in the last 90 days and 17 external contributors on record. MailerSend shows 499 stars across 22 public repos, 12 active in the last 90 days and 7 external contributors.

Klaviyo is the stronger read for anyone weighting community. MailerSend looks better where education is the deciding factor. The table below breaks the scores down pillar by pillar; the linked profiles cover the underlying repos, docs and community signals in full.