This study seeks to develop and then perform a controlled efficacy Randomized Controlled Trial assessing tobacco abstinence of a best-practices Web-based PC-delivered smoking cessation intervention (QuitOnline) compared to a Mobile Smartphone-delivered intervention (MobileQuit). Study participants are randomized to one of two conditions: a Web Only intervention and the Web+Mobile intervention. The hypothesis is that the Web+Mobile approach will yield greater efficacy than the Web Only condition.

The primary aims of this project are to:

1. Use an iterative formative development process to create two separate Web-based smoking cessation programs (Web+Mobile, Web Only).
2. Compare the efficacy of the two smoking cessation programs in terms of tobacco abstinence. The investigators hypothesize that the Web+Mobile condition will be significantly more efficacious in terms of tobacco abstinence than the Web Only condition.
3. Evaluate program usage/participant engagement, treatment acceptability, and consumer satisfaction. The investigators hypothesize that both conditions will be acceptable and that the Web+Mobile condition will have significantly greater usage and higher consumer satisfaction than the Web Only condition.

The secondary aims of this proposal are to:

1. Evaluate the differences between conditions on ancillary tobacco outcomes. The investigators hypothesize that the participants assigned to the Web+Mobile condition who continue to smoke will nonetheless report a greater decline in the smoking rate and more quit attempts.
2. Evaluate predictors and condition moderators of tobacco abstinence. The investigators will conduct exploratory analyses of the association of treatment outcomes to participant characteristics (e.g., baseline smoking rate, nicotine dependence level, partner's tobacco use, prior quitting attempts, prior use of pharmacological adjuncts, and other demographic factors).
3. Evaluate putative mechanisms of change. The investigators will test whether change in the putative mechanisms of change (i.e., self-efficacy, program use, use of pharmacological adjuncts) mediate the association between the intervention condition and 3-month sustained abstinence from the 3 month to 6 month assessments.

Inclusion Criteria:

• ≥ 18 years of age
• Cigarettes are primary tobacco of use
• Smoke ≥ 5 cigs/day for the previous 6 months
• Want to quit in next 14 days
• Use a smartphone and willing to potentially receive/send up to 150 text messages over the six months of the program
• Access to the Internet
• Have a valid personal e-mail address
• Be a U.S. citizen