Policy makers should understand people’s attitudes towards opt-out nudges to smoothly promote and implement the policies. Our research compares people’s perceptions of opt-in and three improved versions of opt-out (transparency, emphasis on the low-cost opt-out option, education) in pro-social and pro-self policy domains, e.g., organ donation (N=610), carbon emission offset (N=613), and retirement saving (N=602). We found that people acknowledged more practical and societal benefits of opt-out than opt-in in organ donation and retirement saving but less so in carbon emission offset. Improved opt-out policies failed to address ethical concerns and most emotional discomfort concerns in organ donation whereas opt-out transparency and emphasis on low-cost opt-out were more successful than education at addressing concerns in retirement saving and carbon emission offset. Nonetheless, transparency and education may raise consciousness of policies’ aims. The results suggest that 1) acceptability of opt-out approaches may be more difficult to enhance in some domains than others; 2) policy makers should ensure the public understands that opt-out is a convenient choice and may consider combining all forms of improvement to increase people’s acceptance of opt-out nudges.