The CES-D (Center for Epidemiological Studies-Depression) and the EAS (Emotionality Activity Sociability Temperament Survey for Children) are two highly respected instruments in the field of psychology. Even though they cater to different demographics and capture distinct dimensions of emotional and social functioning, there exist overlaps which can open up intriguing fields for cross-comparative studies. However, to effectively compare CES-D and EAS, it is crucial to harmonise these two measures which is a intricate process. This is where Harmony, a groundbreaking software developed for psychologists, comes in. Harmony utilises natural language processing and generative AI models to automize the process of questionnaire harmonisation. This powerful tool can compare each item in CES-D and EAS and provide a percentage match, effectively easing the painstaking process of manual comparison. The tool promises to open up a new avenue for researchers interested in a CES-D vs EAS comparative analysis. Harmony’s capabilities are not confined to English instruments alone, it also possesses the remarkable ability to compare items in multiple languages. To use Harmony for comparing CES-D vs EAS, researchers can either select from the database of Harmony or opt to upload their own versions of these instruments. This kind of cross-instrumental analysis can provide valuable insights into common themes and distinct aspects of both measures. Essentially, Harmony acts as an essential tool to fuel innovative research studies in CES-D vs EAS. The simplicity and accessibility of Harmony’s web interface at https://harmonydata.ac.uk/app further add to its appeal for researchers worldwide keen on conducting CES-D vs EAS studies.