Open WebUI vs vLLM

Open WebUI (On a mission to build the best AI user interface.) and vLLM both appear on the Smoower Developer Ecosystem Index.

vLLM (rank #85) holds a narrow lead over Open WebUI (rank #141) on the overall Smoower ecosystem score (58 vs 53). The gap of 5 points reflects composite signals across code, docs, community and reach.

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

Open WebUI carries 173,687 GitHub stars across 26 public repos, with 10 repositories active in the last 90 days and 139 external contributors on record. vLLM shows 131,658 stars across 52 public repos, 43 active in the last 90 days and 1,044 external contributors.

Open WebUI is the stronger read for anyone weighting reach. vLLM looks better where code quality 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.