Advance online check-in - (30 days to 8 days before each flight) is only available to customers who select to purchase an allocated seat.
General Allocated Seats - Customers who don’t wish to pay for a Premium or Regular allocated seat can check-in online between 7 days to 2 hours prior to each flight and will be allocated a seat free of charge.
If you choose to select & purchase an allocated seat there are 2 types of allocated seats available:
Premium Seats - Rows 1-5 (rapid exit), Rows 16 & 17 (extra leg room) and Rows 32 & 33 (rapid exit). Available from £/€ 10 (including Priority Boarding)
Regular Seats - Rows 6-15 & 18-31 available from £/€5. These seats can be upgraded to include Priority Boarding for a small supplement of £/€2.
Ryanair Customer Services