That depends on what your security concerns are. For me, I think it is totally safe to buy things online with your phone. I would do just about anything but financial activities in this context. However, my answer is a bit loaded so now I need to explain that part a bit. Credit Cards have built in protections. If you check your statements and dispute all charges that you did not authorize, then shopping through your phone is completely safe. I have had tons of fraudulent activity on my credit cards and I haven't paid a single cent that wasn't my own charge. The catch here is that you run pretty much the same risk doing your shopping online through an ordinary computer. Granted, phones have terrible security. My real point here is that you should use your phone assuming you cannot trust it. In this case, I use my credit card fraud protection as my mitigation for an untrustable platform.