For the vast majority of airlines, the answer is no; web check-in typically opens only 24 to 48 hours before the scheduled departure time. For example, major carriers like Air India, United, and Lufthansa strictly adhere to a 48-hour window for international flights and 24 hours for domestic. However, some low-cost carriers, such as Ryanair and easyJet, allow passengers who have purchased a specific seat assignment to check in as early as 30 days in advance. If you have not paid for a seat, these airlines usually limit check-in to 24–48 hours before the flight. In 2026, many "smart" travel apps and airline systems offer an "auto-check-in" feature that you can authorize weeks in advance; the system will then automatically perform the web check-in the moment the window opens, securing your digital boarding pass and seat without you having to log in manually at the 24-hour mark.