For experimental research on language production, temporal precision and high quality of the recorded audio-files are mandatory. These requirements are a considerable challenge if language production is to be investigated online. However, online research has a huge potential regarding efficiency, ecological validity and diversity of study-populations in psycholinguistic and related research, also beyond the current situation. Here, we supply confirmatory evidence that language production can be investigated online and demonstrate that the written naming responses (using the keyboard) are a reliable and efficient alternative to typical overt verbal responses. To assess semantic interference effects in both modalities we performed two pre-registered experiments (n=30 each) in online settings using the participants’ web-browsers. A cumulative semantic interference (CSI) paradigm was employed that required naming several exemplars of semantic categories within a seemingly unrelated sequence of objects. Reaction time (RT) is expected to increase linearly for each additional exemplar of a category. In experiment 1, CSI effects in naming times described in lab-based studies were replicated. In experiment 2, the responses were typed on participants’ computer keyboards and the first correct key press was used for RT analysis. This novel response assessment yielded a qualitatively similar, very robust CSI effect. Besides technical ease of application, collecting typewritten responses and automatic data preprocessing substantially reduce the work load for language production research. Results of both experiments open new perspectives for research on RT-effects in language experiments across a wide range of contexts. JavaScript- and R-based implementations for data collection and processing are available for download.