Do Germany passport holders need a visa to visit SI?

No visa. German citizens enjoy EU free movement and can enter Slovenia for tourism with just a valid national ID card or passport, with no time limit on EU citizens beyond a 3-month residence-registration threshold. Germany and Slovenia are both members of the European Union and the Schengen Area, so German nationals travel under EU freedom-of-movement rules. A German ordinary passport holder needs no visa, no ETIAS, and no entry permit to visit Slovenia for tourism. Entry is granted on the basis of a valid German national identity card (Personalausweis) or a valid passport — either document is accepted, and it only needs to be valid on the day of travel. Because both countries are inside the Schengen zone, there are normally no systematic checks at the internal border, though Slovenia has at times reintroduced temporary controls on its borders with Croatia and Hungary, so carrying a valid ID document is essential. The Schengen 90/180-day short-stay rule does NOT apply to EU citizens; instead, a German citizen may stay in Slovenia for up to three months without any formality. For stays beyond three months, an EU citizen must obtain a residence registration certificate from the local administrative unit (upravna enota), but this is a registration step, not a visa. ETIAS, the EU travel authorisation launching for visa-exempt non-EU nationals, does not apply to EU citizens such as Germans. EES (Entry/Exit System) biometric registration likewise targets non-EU travellers, not EU nationals.