Online card sorting applications increase the accessibility of running a card sort. They make it fast, cheap, and easy (depending on the scope and scale of the sort) to set up the sort, and to recruit participants. Also, the participants can complete the sort at their convenience. Another major time-saver of using an online tool is that the data is recorded as the participant performs the sort, rather than having to be compiled and manually entered afterwards.
Some drawbacks of using an online tool for card sorting (as with using any online tool to replicate any manual process) are that the tool can impose its own constraints on the process, and there is also always a chance that technical issues will frustrate the participant or cause the participant to abort the process altogether. Also, an online sort doesn’t provide any verbalized cues about the participant’s organizational rationale. Although this could be overcome by using a card sort tool such as OptimalSort with a screensharing or conferencing tool to run a remote moderated sort.