INTRODUCTION: To achieve epidemic control of infectious diseases, engaging higher-burden populations with accessible diagnostic services is critical. HIV self-testing (HIVST) is a promising option. METHODS: We implemented an online HIVST programme for key populations across India. Eligible clients were 18 years or older, self-reported a negative or unknown HIV status and reported not taking antiretroviral therapy. Clients who reported a prior HIV diagnosis were not eligible to receive an HIVST kit. HIVST clients received kits via courier or in person at pre-determined pick-up points supported by trained counselling staff. Virtual counsellors engaged clients online and by phone and offered support to register, access, and complete HIVST free of cost. Virtual counsellors supported clients to report results and engage with follow-up services. Follow-up included linking clients with a positive result to confirmatory testing and HIV care services. We assessed programmatic data across HIV continuum outcomes and conducted a qualitative evaluation through interviews with purposively sampled clients. RESULTS: Between 30 June 2021 and 30 September 2022, 5324 clients ordered an HIVST kit (76% men, 13% women, 7% transgender people, 4% unknown gender). Of the 4282 clients reporting results (94% of those who received a kit), 6% screened positive, among whom 72% (n = 184) completed confirmatory testing. Themes from 41 client interviews included satisfaction about the convenience and privacy of services and the discreet nature of kit delivery. Respondents were drawn to the convenience of HIVST and appreciated gaining courage and comfort throughout the process from virtual counsellor support. For respondents who screened positive, challenges to care linkage included fearing judgemental questions from public providers and wanting more time before starting treatment. Clients shared concerns about kit accuracy and suggested that instructional materials be provided with more diverse language options. CONCLUSIONS: Web-based HIVST services with tailored support appeared to facilitate HIV service access and engagement of harder-to-reach populations across India. Assistance from a community-oriented counsellor proved important to overcome literacy barriers and mistrust  in order to support the HIVST process and service linkage. Learnings can inform global efforts to improve the critical step of diagnosis in achieving epidemic control for HIV and other infectious diseases.