Click-through rate (CTR) is a metrics that measures the percentage of viewers who click on a video after being shown its thumbnail and title as an impression. On YouTube, CTR is one of the most direct signals of how well your thumbnail and title combination performs. A higher CTR tells the algorithm that your content is compelling and relevant to the audience being shown it, which can increase distribution across Search, Home, and Suggested feeds. CTR is typically benchmarked alongside viewer retention — strong performance in both signals healthy, high-quality content to the platform.