Sleep assessment is a fundamental part of health evaluation. In fact, many diseases (such as obesity, diabetes, or hypertension, as well as psychiatric, neurological, and cardiovascular diseases) produce sleep disorders that are often used as indicators, diagnosis (symptoms), or even as predictors (eg, for depression) of health. For this reason, many efforts have been devoted to designing methods to control and report on sleep quality. Two of the most used sleep assessment tools are sleep questionnaires and sleep diaries. Both methods have a very low cost are easy to administer do not require a sleep centre (unlike, eg, polysomnography), and can be self-administered. Most important, as it has been shown in recent studies, their accuracy is relatively high. In this survey, we systematically review and compare these tools. We examine the evolution of sleep questionnaires and diaries over time, and compare their structure and usage. We also review the validation studies and comparatives performed in previous studies. This allows us to compare the relative sensitivities and specificities of these methods. Modern sleep diaries come in the form of an app. Therefore, we also present the most advanced and used apps, and discuss their advantages over classical paper diaries.