AimIt remains undetermined whether online education videos for Japanese patients with chronic kidney disease (CKD) are easy to understand and allow adoption of behavioural changes. This study quantitatively assessed the understandability and applicability of online education videos for patients with CKD.MethodsIn September 2021, we identified 200 videos on YouTube using the Japanese translations of the keywords ‘kidney,’ ‘kidney disease,’ ‘CKD,’ and ‘chronic kidney disease.’ We used the Japanese version of the Patient Education Materials Assessment Tool to evaluate the understandability and usability of webpages on a scale of 0% to 100%. The cut‐off was set at 70%.ResultsA total of 54 videos were evaluated. The overall understandability and actionability of the materials were 57.6 (SD = 22.6) and 53.7 (SD = 33.4), respectively. Approximately 70% and 60% of the materials were considered insufficiently understandable and actionable, respectively. Most videos lacked a summary and had difficulty in using only everyday language. Most videos included at least one action for the audience to take. However, many failed to break down the action into sequential steps. They also lack visual aids to encourage the audience to take action.ConclusionOur results suggest that current information on pre‐dialysis chronic kidney disease was not presented in a manner that can be applied by laypeople.