•Asthma is a heterogeneous disease with several phenotypes and endotypes and Biomarkers help in the phenotyping and endotyping of asthma.•Biomarkers should be clinically applicable and act as surrogate markers to reflect disease mechanisms, predict the course of disease, and response to certain therapies.•Only few biomarkers that reflect T2 airway inflammation are currently readily available for clinical use.•There is a great unmet need for biomarkers reflecting T2-Low asthma.•Use of composite biomarkers may prove to be of greater importance than a single biomarkers but that needs further evaluation. Severe asthma is heterogeneous in its clinical presentation, underlying pathophysiology, course and response to therapy. Clinical and physiological assessment of severe asthma is often inadequate in predicting underlying disease mechanisms and or response to medications. With the emergence of novel targeted therapies in severe asthma, the need for reproducible, easily measured biomarkers became obvious but only few are currently available for clinical use. These biomarkers along with the clinical presentation of the patient play an important role in identifying phenotypes and endotypes, predicting the clinical course and prognosis and improving the precision therapeutic approach to asthma.