In March 2020, weeks before the World Health Organization (WHO) declared COVID-19 a pandemic, its director-general Tedros Adhanom Ghebreyesus delivered a speech in which he emphasised the importance of testing: The pandemic exposed critical shortcomings of existing diagnostic techniques. It revealed an urgent need for tests that are faster, simpler, cheaper and more scalable than existing methods, and just as accurate. Three years on, the global face of diagnostics has changed.