A web and mobile app where users photograph or describe their existing door hardware and answer a short guided questionnaire (door thickness, lock type, connectivity preferences, smart home ecosystem, region, budget). The tool cross-references a curated, regularly updated database of smart lock specs to return ranked, compatible recommendations with install difficulty ratings, app quality scores, and offline/cloud trade-off summaries. An optional AI chat layer answers follow-up questions and flags edge cases like double doors, non-standard deadbolts, or local-only setups.

The smart lock market is projected to exceed $4B globally by 2027, yet discovery remains entirely search-and-forum-based with no structured compatibility layer. Privacy-conscious buyers increasingly demand offline-first options, creating a new filtering dimension that generic retail sites completely ignore.