HK-VMT is a free web-based computerized cognitive screening for detecting early cognitive deficits in older people who are at risk of developing dementia. Unlike conventional cognitive screening, the online platform can be self-administered and performed from any desktop computers or iPads. The screening focuses on subtle deficits such as complex attention and processing speed that are not included in conventional screening. In addition, the test items are presented in random order with three alternative versions to minimize practice effect. Most importantly, it can identify early subtle cognitive changes in the highly educated older populations, who may easily be dismissed by clinicians. Service providers will get an authorized hyperlink for unlimited use, so they do not need to download or install any software onto their computers or tablets. HK-VMT helps frontline workers to differentiate older adults with early cognitive deficits from normal cognitive ageing, so elderly centers can effectively allocate resources for early cognitive training to the at-risk group. In addition, the benefit of detecting early subtle cognitive changes in the preclinical stage is that people can start early to intervene on many risk factors through low-cost lifestyle modification to delay dementia onset. In the long run, it can help to cut healthcare costs associate with dementia care.