Lounge Frog guide

Frontier Airlines Airbus A321neo (243 seats) vs United Airlines Airbus A321neo (200 seats)

Frontier Airlines Airbus A321neo (243 seats) has 243 seats and United Airlines Airbus A321neo (200 seats) has 200. Only the second has First.

Cabins side by side

Cabin	Seats	Rows	Layout	Seat	Pitch	Width	Recline	Wi-Fi
Frontier Airlines · 243 seatsUpFront Plus	12	1–2	3-3	—	—	—	—	—
Frontier Airlines · 243 seatsEconomy	231	3–41	3-3	—	—	—	—	—
United Airlines · 200 seatsUnited First	20	1–5	2-2	Recliner	37 in	21 in	5 in	Yes
United Airlines · 200 seatsUnited Economy	180	7–42	3-3	Recliner	30 in	18.4 in	2 in	Yes

243 seats: 21 good, 18 mixed, 11 to avoid

Row 1, seats A and C (UpFront Plus): upFront Plus front row: extra legroom, the middle seat kept empty and nobody reclining into you, though the forward lavatory is just ahead on this side. Frontier offers no seatbelt extensions in row 1 and doesn't seat infants there.
Row 1, seats D and F (UpFront Plus): upFront Plus front row: extra legroom, the middle seat kept empty and nobody reclining into you; the block ahead on this side is likely the galley. Frontier offers no seatbelt extensions in row 1 and doesn't seat infants there.
Row 2, seats A, C, D and F (UpFront Plus): upFront Plus: extra legroom near the front, and Frontier guarantees the middle seat beside you stays empty.
Row 3, seats A, C, D and F (Economy): premium row right behind UpFront Plus: extra legroom close to the front, without the UpFront Plus price.

Row 17, seats A, B, C, D, E and F (Economy): row in front of the overwing exits: recline is likely limited (Frontier's map doesn't say), with no exit-row legroom of its own.
Row 28, seats A, B, C, D and E (Economy): row in front of the mid-cabin exit door: recline is likely limited (Frontier's map doesn't say).

200 seats: 48 good, 13 mixed, 14 to avoid

Rows 8–11 and 22, seats A, B, C, D, E and F (United Economy): united Economy Plus: about 33" of pitch, against 30" in Economy
Row 21, seats A, B, C, D, E and F (United Economy): exit row with extra legroom
Rows 23–26, seats D, E and F (United Economy): united Economy Plus: about 33" of pitch, against 30" in Economy

Row 5, seats A and B (United First): next to a lavatory, with queues, noise and flushing
Row 16, seats A, B, C, D, E and F (United Economy): united lists zero recline at row 16.
Row 41, seats D, E and F (United Economy): united lists 1 inch of recline at 41D, 41E and 41F.
Row 42, seats A, B and C (United Economy): next to a lavatory, with queues, noise and flushing