Introduction Anosmia can have a significant impact on well-being and quality of life. Due to an ageing population and the coronavirus disease 2019, increasing numbers of patients are seeking online information on anosmia. This report systematically assesses the readability and quality of online information on anosmia. Methods The terms ‘anosmia’ and ‘loss of smell’ were entered into Google. The first 50 websites generated for each search term were screened. Readability was assessed using the Flesch–Kincaid Reading Ease Score (FRES), Flesch–Kincaid Grade Level (FKGL), Simple Measure of Gobbledygook (SMOG) Index and Gunning Fog Index (GFI). Quality was assessed using the DISCERN instrument. Spearman’s correlation between quality and readability was calculated. Results A total of 79 websites met the inclusion criteria. The mean and 95% confidence interval for the FRES, FKGL, SMOG, GFI and DISCERN scores were 46.31 (42.94–49.68), 12.00 (11.27–12.73), 10.70 (10.16–11.23), 14.62 (13.85–15.39) and 2.90 (2.69–3.11), respectively. Significant negative correlation was noted between the DISCERN and FRES (rs=−0.500; p<0.05). Discussion Online information on anosmia is written above the recommended reading age guidance in the UK, and has moderate deficiencies in quality. As a result, the information may be used inappropriately and could result in worse health outcomes. We recommend that patients are directed to websites produced by health providers or nonprofit organisations that develop material for patient health education. Conclusions Online information on anosmia is of low readability and moderate quality. Healthcare professionals should direct patients towards high-quality resources written for the layperson.