To tackle the fast-moving challenges of our age, law and policymaking must become more flexible, evolutionary and agile. Thus, in this Essay we examine ‘crowdlaw’, namely how city councils at the local level and parliaments at the regional and national level are turning to technology to engage with citizens at every stage of the lawand policymaking process. Aswe hope to demonstrate, crowdlaw holds the promise of improving the quality and effectiveness of outcomes by enabling policymakers to interact with a broader public using methods designed to serve the needs of both institutions and individuals. crowdlaw is less a prescription for more deliberation to ensure greater procedural legitimacy by having better inputs into lawmaking processes than a practical demand for more collaborative approaches to problem solving that yield better outputs, namely policies that achieve their intended aims. However, as we shall explore, the projects that most enhance the epistemic quality of lawmaking are those that are designed to meet the specific informational needs for that stage of problem solving.