Background: Tobacco vaporizers are devices that heat tobacco without burning it. There is currently a scarcity of studies about the addictiveness of tobacco vaporizers or their effects on cigarette withdrawal symptoms. Goals: To assess the perceived dependence of users of tobacco vaporizers and the perceived effects of these products on cigarette withdrawal symptoms. Methods: Enrollment of participants through the internet from 2016 to 2018. Participants were self-selected visitors to an anti-addiction website, current and past users of tobacco vaporizers aged ≥18. Results: We included 139 users of IQOS tobacco vaporizers. All participants were current (49.6%) or former cigarette smokers at the time when they began to use the tobacco vaporizer. Among the 135 current users, the median dependence on vaporizers was 80 on a scale from 0-100 (25th and 75th percentiles: 50 and 90), and 63.6% reported being somewhat to totally afraid of becoming dependent on the vaporizer. Half (51%) reported that they were less dependent on vaporizers than on combustible cigarettes, 43.8% were equally dependent on both products and 5.2% were more dependent on vaporizers than on cigarettes. Only one cigarette withdrawal symptom was reported by participants, "craving" for combustible cigarettes, and among respondents who experienced craving, 83.9% found that the IQOS vaporizer relieved it "a lot" to "totally". Conclusions: In this self-selected online sample of IQOS users, the perceived dependence on this tobacco vaporizer was relatively high and almost two thirds of respondents were afraid of becoming dependent on IQOS. Most participants perceived that IQOS relieved the craving to smoke combustible cigarettes.