The characters literally combine to mean “Seats (座) without (无) empty (虚) seats (席).” The repetition of the concept “seat” with both 座 and 席 is a common feature in classical Chinese idioms, used for emphasis and rhythmic balance. The phrase elegantly means “not a single empty seat to be found.”
In Chinese culture, a bustling, lively atmosphere, known as 热闹 (rènao), is often seen as a sign of success, prosperity, and joy. A venue that is 座无虚席 is the epitome of 热闹 for an organized event. It signifies that the performance, lecture, or gathering is highly anticipated and valued by the community. For the organizers, achieving a state of 座无虚席 brings great 面子 (miànzi), or “face,” which is social prestige and reputation. It's a public validation of their efforts and the appeal of their offering. Compared to the English phrase “a packed house,” 座无虚席 carries a more formal and literary tone. While you might casually say a local bar was “packed,” using 座无虚席 for such a situation would be overly formal. The Chinese idiom is better suited for contexts where seating is pre-arranged and the full attendance is a measure of the event's official success, much like a critic writing that a Broadway show had “a full house on opening night.”
座无虚席 is primarily used in more formal or descriptive contexts.
The connotation of 座无虚席 is almost always positive, as it implies high demand and success.