Digital Technologies in Tobacco Cessation: A Narrative Review of Smartphone Applications, Web-Based Programmes, and AI Conversational Agents

Background: Tobacco smoking causes over eight million deaths annually and remains the leading preventable cause of disease worldwide (World Health Organization, 2023). Structural barriers limit access to counselling and pharmacotherapy, motivating the development of digital cessation tools across three modalities: smartphone applications, web-based programs, and AI conversational chatbots. Objective: This narrative review synthesises peer-reviewed evidence (2021–2026) on the efficacy, engagement, and equity of digital smoking-cessation interventions across these three modalities. Methods: PubMed and PMC were searched using MeSH and free-text terms for smoking cessation combined with smartphone applications, eHealth, SMS, chatbots, and artificial intelligence. Primary studies enrolled smokers aged ≥16 years reporting abstinence outcomes; secondary literature included systematic reviews, meta-analyses, and qualitative evaluations. Findings were synthesised thematically. Results: Smartphone apps combined with pharmacotherapy outperformed medication alone (OR 1.79, 95% CI 1.38–2.33; Guo et al., 2023), whereas standalone apps were non-significant. A 152-RCT network meta-analysis (Li et al., 2025) ranked personalized digital interventions above standard care (RR 1.86, 95% CI 1.54–2.24). AI chatbots showed early positive signals, including biochemically verified 6-month abstinence rates of 26.0% versus 18.8% under usual care (Olano-Espinosa et al., 2022). Engagement decay, self-reported outcomes, and limited population diversity were consistent weaknesses. Conclusions: Digital tools deliver clinically meaningful benefits when grounded in behavioural science frameworks and integrated with pharmacotherapy or human support. Future research needs to prioritise head-to-head comparisons, biochemically verified outcomes, equity-centred deployment, and moral governance for AI-delivered support.