Abstract Purpose To assess the test–retest reliability of the EQ-5D-5L and the reworded Quality of Life After Traumatic Brain Injury Overall Scale (QOLIBRI-OS) for the general population of Italy, the Netherlands, and the United Kingdom (UK). Methods The sample contains 1864 members of the general population (aged 18–75 years) of Italy, the Netherlands, and the UK who completed a web-based questionnaire at two consecutive time points. The survey included items on gender, age, level of education, occupational status, household annual income, chronic health status, and the EQ-5D-5L and reworded QOLIBRI-OS instrument. Test–retest reliability of the EQ-5D-5L dimensions, EQ-5D-5L summary index, EQ VAS, reworded QOLIBRI-OS dimensions and reworded QOLIBRI-OS level sum score was examined by Gwet’s Agreement Coefficient (Gwet’s AC) and Intraclass Correlation Coefficient (ICC). Results Gwet’s AC ranged from 0.64 to 0.97 for EQ-5D-5L dimensions. The ICC ranged from 0.73 to 0.84 for the EQ-5D-5L summary index and 0.61 to 0.68 for EQ VAS in the three countries. Gwet’s AC ranged from 0.35 to 0.55 for reworded QOLIBRI-OS dimensions in the three countries. The ICC ranged from 0.69 to 0.77 for reworded QOLIBRI-OS level sum score. Conclusion Test–retest reliability of the EQ-5D-5L administered via a web-based questionnaire was substantial to almost perfect for the EQ-5D-5L dimensions, good for EQ-5D-5L summary index, and moderate for the EQ VAS. However, test–retest reliability was less satisfactory for the reworded QOLIBRI-OS. This indicates that the web-based EQ-5D-5L is a reliable instrument for the general population, but further research of the reworded QOLIBRI-OS is required.