Background: User onboarding is a critical phase in web applications that significantly impacts user retention and perceived value. Although various onboarding strategies exist, there is a lack of comparative empirical evidence on their relative effectiveness, particularly concerning newer approaches such as nudging and LLM-powered chatbots in complex SaaS setup contexts.

Objectives: This study aims to systematically evaluate and compare the effectiveness of five different onboarding strategies - wizards, interactive walkthroughs, gamification, nudging and LLM chatbots - within the same application environment to determine which best guides users through essential setup tasks.

Methods: A quasi-experimental approach was implemented using a multi-armed bandit strategy, where 620 real users of Lapsula.com, a SaaS platform for the health and wellness industry, were dynamically assigned to different onboarding strategies based on their performance. The UCB (Upper Confidence Bound) algorithm was used to optimize strategy allocation after an initial uniform distribution. Effectiveness was measured through completion rates, completion time, partial completion percentages, and user satisfaction ratings.

Results: Interactive walkthroughs demonstrated the highest completion rate (52.43%) and satisfaction (94.85%), while LLM chatbots had the lowest completion rate (19.15%) but the fastest completion time (5.85 days) and high satisfaction (94.44%) among participants. Wizards showed moderate performance with the second highest completion rate (41.45%) but the longest completion time. Nudging performed poorly in satisfaction (22.73%), despite moderate completion times, while Gamified checklists did slightly better.

Conclusions: The choice of onboarding strategy significantly impacts user success and satisfaction, with this experiment suggesting that interactive walkthroughs provide a solid approach for complex SaaS applications. This research provides an evidence-based foundation for designing effective onboarding experiences that balance user autonomy with a very directed and goal-oriented approach.