15Five vs Duolingo

15Five and Duolingo both appear on the Smoower Developer Ecosystem Index.

Duolingo (rank #338) holds a modest lead over 15Five (rank #693) on the overall Smoower ecosystem score (43 vs 31). The gap of 12 points reflects composite signals across code, docs, community and reach.

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

15Five carries 141 GitHub stars across 29 public repos, with 2 repositories active in the last 90 days and 5 external contributors on record. Duolingo shows 1,721 stars across 12 public repos, 8 active in the last 90 days and 11 external contributors. The star gap on its own does not decide the comparison, but Duolingo's footprint is roughly 12.2x larger, which usually shows up in downstream signals like inbound issues and third party integrations.

15Five is the stronger read for anyone weighting education. Duolingo 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.