Dunkerque, overall, is a relatively safe city to visit. Petty crime such as pickpocketing can occur, especially in crowded places and public transport, so be vigilant about your belongings. However, violent crimes are uncommon. It's also wise to avoid traveling alone at night in less crowded areas. Locals are generally helpful and friendly. Even though it is safe, it is always best to be aware of your surroundings and take precautions.