Chronic breathlessness is a common, burdensome and distressing symptom in many advanced chronic illnesses. Self-management strategies are essential to optimise treatment, daily functioning and emotional coping. People with chronic illness commonly search the internet for advice on self-management. A review was undertaken in June 2015 to describe the content and quality of online advice on breathlessness self-management, to highlight under-served areas and to identify any unsafe content. Google was searched from Sydney, Australia, using the five most common search terms for breathlessness identified by Google Trends. We also hand-searched the websites of national associations. Websites were included if they were freely available in English and provided practical advice on self-management. Website quality was assessed using the American Medical Association Benchmarks. Readability was assessed using the Flesch-Kincaid grades, with grade 8 considered the maximum acceptable for enabling access. Ninety-one web pages from 44 websites met the inclusion criteria, including 14 national association websites not returned by Google searches. Most websites were generated in the USA (n=28, 64%) and focused on breathing techniques (n=38, 86%) and chronic obstructive pulmonary disease (n=27, 61%). No websites were found to offer unsafe advice. Adherence to quality benchmarks ranged from 9% for disclosure to 77% for currency. Fifteen (54%) of 28 written websites required grade ≈ 3/49 reading level. Future development should focus on advice and tools to support goal setting, problem solving and monitoring of breathlessness. National associations are encouraged to improve website visibility and comply with standards for quality and readability.