15Five vs Grammarly

15Five and Grammarly (Millions of users rely on Grammarly's AI-powered products to make their messages, documents, and social media posts clear, mistake-free, and impactful.) both appear on the Smoower Developer Ecosystem Index.

Grammarly (rank #600) holds a narrow lead over 15Five (rank #696) on the overall Smoower ecosystem score (34 vs 31). The gap of 3 points reflects composite signals across code, docs, community and reach.

On code quality (the state of repositories, tests, releases and polish), Grammarly is slightly ahead of 15Five. On education (docs, guides and learning material for developers), Grammarly is slightly ahead of 15Five. On community (issue response, PR reviews and discussion health), 15Five is slightly ahead of Grammarly. On reach (how visible the ecosystem is beyond its own repos), Grammarly is clearly ahead of 15Five. On momentum (release cadence and how fast the ecosystem moves), 15Five is slightly ahead of Grammarly.

15Five carries 142 GitHub stars across 29 public repos, with 2 repositories active in the last 90 days and 4 external contributors on record. Grammarly shows 4,356 stars across 23 public repos, 0 active in the last 90 days and 0 external contributors. The star gap on its own does not decide the comparison, but Grammarly's footprint is roughly 30.7x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

15Five is the stronger read for anyone weighting momentum. Grammarly looks better where reach 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.