This paper studies the impact of Generative AI technology on the demand for online freelancers using a large dataset from a leading global freelancing platform. We identify the types of jobs that are more affected by Generative AI and quantify the magnitude of the heterogeneous impact. Our findings indicate a 21% decrease in the number of job posts for automation-prone jobs related to writing and coding compared to jobs requiring manual-intensive skills after the introduction of ChatGPT. We also find that the introduction of Image-generating AI technologies led to a significant 17% decrease in the number of job posts related to image creation. Furthermore, we use Google Trends to show that the more pronounced decline in the demand for freelancers within automation-prone jobs correlates with their higher public awareness of ChatGPT’s substitutability.