The theme of the “constitutional” rules for the Internet is presented in this essay as linked with a more recent question relating to the algorithmic decision-making. The reasoning is structured upon two different, although related, topics. Firstly, the choice of the regulatory model best suited for the Internet is considered: hard or soft law. Secondly, the issues of constitutional legitimacy arising from each model are dealt with at the national and European levels. The algorithms are assumed as a test for the resistance or disruptiveness of the traditional legal categories concerning fundamental rights and relation between public powers. They also provide the challenge to design new reasonable paradigms. This paper will discuss if and how the policy maker should take into account the visibility and the intelligibility of algorithms. Therefore, a binding regulation, although held to a minimum, will be able to draw an algorithm in accordance with the European Constitutional values, in other terms an ‘algorithm Constitutional by design’. In more general prospective, this paper will guide technology towards a fair and widespread common good in compliance with a democratic institutional framework.