Yes, 100% of checked luggage is scanned at commercial airports, though the process is usually "invisible" to the passenger. After you drop your bag at the check-in counter, it travels on a conveyor belt into a secure "back-of-house" area. Here, it passes through a high-tech Explosive Detection System (EDS), which is essentially a massive, high-speed CT scanner. These machines use 3D X-ray technology to analyze the density of every object in your bag, looking for the specific chemical signatures of explosives or prohibited items. If the machine flags an "anomaly" that it cannot identify, a TSA officer (or local security) will be alerted to perform a manual bag search. This is why you might find a "Notice of Baggage Inspection" slip inside your bag upon arrival. In 2026, these scanners have become so advanced they can distinguish between a harmless block of cheese and plastic explosives, but they still struggle with "dense clutter," which is why neatly packed bags are less likely to be opened. Every bag is also screened for radiation and, on some international routes, "sniffed" by specialized K9 units or "electronic noses" for narcotics.