Abstract: In life-threatening emergencies, citizens need to be warned. The currently used method for citizens warning in The Netherlands is a siren. AT this moment, research is being carried out into using new technologies as an addition to this siren for citizens warning. Modern telecommunication technologies have great potential for informing the public. Especially the use of text-based features of mobile phones is considered for this function. Advantages of such a system are that these technologies overcome problems of hearing the siren and that text-based messages provide possibilities for giving more and more detailed information. In a number of pilot studies, Delft University of Technology has gained experience with the possibilities of these technologies for citizens warning services. This paper compares two text-based mobile phone technologies that can be used for citizens warning as an addition to the siren.