Background Subtle cognitive changes have been described that may predate the onset of clinically recognizable Alzheimer's disease (AD) and may reflect pathological changes in the brain that are detectable up to 10 years before the onset of AD. Early screening for cognitive status can have benefits in terms of early management and prevention strategies for cognitive decline. Method A novel computerized cognitive screening tool, the Cognitive Function Test (CFT), was compared with established paper tests of episodic memory, executive function and processing speed, domains previously shown to be predictive of AD, with 50 normal participants, Mini Mental State Examination ≥24, mean age 58.1, SD 5.6 years (range 50–65). An online version, self‐administered by 195 eligible respondents without significant memory complaints or dementia, was assessed. Results Significant correlations (r = 0.75, p < 0.0001) were found between the CFT and paper tests in a pilot study, showing concurrent validity. The pilot computerized tests were compared with the online version, and no differences were found in mean scores on the total test and domain‐specific scores using an algorithm derived from the pilot CFT scores, thus showing internal consistency and reliability of the online format. Norms and 1.5 SD cut‐offs for the CFT are presented. Conclusion The online CFT was shown to be suitable for self‐administration in online format (with a mouse response mode) for this midlife age group. Individuals may wish to monitor their cognitive performance before memory concerns are sufficient to warrant visiting a GP or memory clinic. Copyright © 2013 John Wiley & Sons, Ltd.