Abstract: An online system uses a visual positioning system (VPS) model to verify the location of a client device for anti-spoofing measures. The online system receives ostensible pose data and image data from the client device. This pose data and image data are ostensibly captured by the client device at the same time, or within some threshold time of each other. The online system determines whether they match according to a VPS model. The online system uses the VPS model to output candidate poses for the client device based on the received image data and compares those candidate poses to the pose in the received pose data. If the differences between the candidate poses and the pose from the received pose data exceed a threshold, the online system may determine that the received pose data and image data do not match and thus are likely being spoofed.