Click-Through Rate (CTR) is a digital marketing metric measuring the percentage of people who click a link, ad, or call-to-action out of the total who viewed it, calculated as clicks divided by impressions.
Click-through rate expresses engagement as a ratio: the number of clicks divided by the number of impressions, multiplied by 100 to yield a percentage. A banner ad shown 10,000 times and clicked 50 times has a CTR of 0.5%. The metric applies anywhere a measurable click follows a view — display and search advertising, email campaigns, organic search listings, and on-site calls-to-action.
CTR functions as a proxy for relevance and creative effectiveness: a higher rate generally signals that the message, targeting, and placement resonate with the audience seeing it. Advertising platforms also use it as an input to ad ranking and cost — on search and social networks, ads with stronger click-through rates often earn lower costs and better placement, because the platform is rewarded when users engage.
CTR measures interest, not outcomes, so it is read alongside downstream metrics rather than alone. A high click-through rate paired with weak 📝Return on Ad Spend (ROAS) or low conversion can indicate misleading creative or a mismatch between the ad's promise and the landing experience. Benchmarks vary widely by channel, industry, and format, which makes trend-over-time and within-channel comparison more meaningful than absolute targets.