Urinary tract infections (UTIs) are the most common bacterial infections in women. More than half of all women suffer at least once from a UTI. Current over-the-counter tests are not sensitive enough, and diagnosis of UTI is today based on symptoms only, leading to non-optimal treatment and unnecessary use of antibiotics. We have miniaturized culture-based bacterial detection (gold standard for UTI diagnosis) in a dipstick format with a highly sensitive and quantitative digital bioassay. We can detect and quantify bacteria in the clinically relevant range, without any complicated lab instruments, and with a readout by the naked eye or a simple cell phone camera. The significance and uniqueness of our diagnostic test is that it allows a non-trained operator to detect urinary tract infections in the clinically relevant range in the home setting.