AbstractThe research project aims to develop an e-learning tool named 'CellSplit Insight' with strong validity and assess its usability for teaching cell division in Form 4 Biology. Using a quantitative approach, the tool was developed following the ADDIE model, and its usability was assessed using the USE questionnaire adapted from Lund (2001). The study employed simple random sampling to select 37 students for the pilot test and 77 students for the field test across schools in Malacca. Expert validity, pilot testing, and field testing were conducted to evaluate the tool's validity, reliability, and usability. Data analysis methods included the Content Validity Index (CVI) for expert validity, Cronbach's Alpha for pilot testing, and descriptive analysis (mean and standard deviation) for field testing. Results indicated high validity with a CVI value of 1.0. Usability scores were also favourable across all constructs: usefulness (mean: 3.7857, sd: 0.37547), ease of learning (mean: 3.7857, sd: .....