0001107843 2021-03-19 2021-03-19 false 0001107843 8-K 2021-03-19 Qualys, Inc. DE 001-35662 77-0534145 919 East Hillsdale Boulevard Foster City CA 94404 (650) 801-6100 false false false false Common stock, $0.001 par value per share QLYS NASDAQ false