Is OpenCV better than YOLO?

OpenCV isn't competing with YOLO, so there isn't really a "which is better" answer to give. OpenCV is a general-purpose computer vision library first released in 2000, covering image filtering, camera calibration, and dozens of classical algorithms, while YOLO is a specific family of neural network architectures built for one job: real-time object detection, introduced in a 2015 paper that reported 45 frames per second on a Titan X GPU. OpenCV's own DNN module can load and run a YOLO model directly, so in most real pipelines the two work together rather than compete.