Both tools have similar popularity levels, with Better Auth having 29,486 stars and Keycloak having 36,046 stars on GitHub. In terms of developer contributions, Keycloak has 8,739 forks, indicating strong developer engagement.

Both projects show recent activity, with Better Auth last updated 19 hours ago and Keycloak 13 hours ago.

Both tools share common technology foundations, being built with JavaScript, CSS, Typescript, JSX. However, they differ in their additional technology choices: Better Auth uses Next.js, Vue, SvelteKit, Nuxt.js, Remix, Tanstack Start while Keycloak leverages Bash, Python, C, Java.

Keycloak has been in development longer, starting 13 years ago, compared to Better Auth which began 2 years ago. This 11.0-year head start suggests Keycloak may have more mature features and established processes.

Better Auth uses the MIT license, which is more permissive than Keycloak's Apache-2.0 license, potentially offering greater flexibility for commercial use and integration.

Both tools serve similar use cases in Authentication & SSO. However, they also have distinct specializations: Better Auth also focuses on Identity & Access Management (IAM) while Keycloak extends into Authorization & Permissions.