In recent years, the use of GPUs for general-purpose computations has steadily increased. As security-critical computations like AES are becoming more common on GPUs, the scrutiny must also increase. At the same time, new technologies like WebGPU put easy access to compute shaders in every web browser. Prior work has shown that GPU caches are vulnerable to the same eviction-based attacks as CPUs, e.g., Prime+Probe, from native code.