Psychologists around the world have often faced hurdles while comparing questionnaires like the Center for Epidemiological Studies-Depression (CES-D) and the Inventory of Callous Unemotional Traits (ICU). The process of matching items in these tools, also known as harmonisation, is exhausting and subjective. Here is where the Harmony tool, designed with advanced Natural Language Processing (NLP) and AI algorithms, comes to the rescue. The Harmony tool simplifies the comparison of CES-D vs ICU, producing a percentage match between each item in both tools. The traditional methods of harmonising questionnaires involved going through long PDFs and putting questions into Excel manually, which was not conducive for efficient research. Harmony not only automates this process but also holds capabilities to work with multiple languages. By selecting instruments from Harmony’s database or uploading them in PDF form, comparing CES-D vs ICU becomes extremely streamlined. The intuitiveness of the Harmony web interface, available at https://harmonydata.ac.uk/app, further makes the experience seamless. Choosing Harmony for studying CES-D vs ICU ensures the extraction of valuable insights from cohort and longitudinal studies for clinical research. It assists in analyzing whether results are consistent across studies or differ through changing social conditions. With the capacity to generate detailed comparisons, Harmony is a perfect solution for psychologists aiming to dig deeper into the study of CES-D vs ICU. Its enhanced user experience and precision in results redefines harmonisation, making it an essential utility in psychology research.