The International Particle Physics Outreach Group (IPPOG) is a network of scientists, science educators and communication specialists working across the globe in informal science education and public engagement. IPPOG members activities include the International Particle Physics Masterclasses programme, the International Muon Week and International Cosmic Day organization, as well as a wide spectrum of activities such as public talks, festivals, exhibitions, teacher training, student competitions, and open days at local institutions. These independent activities, often carried out in a variety of languages to public with a variety of backgrounds, all serve to gain the public trust and to improve worldwide understanding and support of science. Special focus will be given to the flagship activity of IPPOG, the particle physics masterclasses, a hands-on activity giving the opportunity to more than 15000 high-school students every year to get a flavor of the way research is done by analyzing data from high energy physics experiments.