PSYCHOACOUSTICS-WEB is an online tool written in javascript and php that enables the estimation of auditory sensory thresholds via adaptive threshold tracking. The toolbox implements the staircase procedures (i.e., the simple up-down and the transformed up-down suggested by Levitt, 1971) for a set of classic psychoacoustical tasks: frequency, intensity, and duration discrimination of pure tones; duration discrimination and gap detection of noises; amplitude modulation detection with noise carriers. The toolbox can be used through a common web browser (it works both with fixed and mobile devices) and requires no programming skills. PSYCHOACOUSTICS-WEB is suitable for laboratory, classroom and online testing and was designed for two main types of users: an occasional user and, above all, an experimenter using the toolbox for his/her own research. This latter user can create a personal account, customise existing experiments and share them in the form of direct links to further users (e.g., the participants of a hypothetical experiment). Finally, because data storage is centralised, the toolbox offers the possibility to set the basis of a database of auditory skills.