When should passengers check-in for their Ryanair flight?

Passengers should check in for their Ryanair flight at least 24 hours before departure to ensure a smooth boarding process. This time frame allows travelers to secure their boarding pass and makes it easier to address any potential issues or changes to their travel plans well in advance. Ryanair offers an online check-in option which opens 24 hours before the scheduled flight departure, reinforcing the importance of this timeframe. Checking in early also provides passengers with better flexibility and potentially lowers the risk of missing their flight due to delays in arrival at the airport or unforeseen circumstances that may occur closer to departure time.

Other options suggest shorter time frames, but they do not account for the online check-in procedures Ryanair has established, which strongly encourage early check-ins. Additionally, the last option indicates that check-in is unnecessary for domestic flights, which isn't consistent with standard airline practices where check-in is always required regardless of the route.