Frontier Airlines also features an all-economy class configuration on its Airbus A320 family fleet. Standard seat pitch ranges from 28 to 29 inches but can reach up to 32 inches on some rows in the A321 variant. Seat width is typically between 17 and 18 inches. Most standard seats do not recline and have minimal padding. Frontier offers Stretch seating with up to five extra inches of legroom in certain rows as well as an UpFront Plus product that blocks the middle seat for added space.

Spirit Airlines is known for offering less legroom than its competitors; standard seats average just 28 inches in pitch with widths between 16 and 17 inches. Seats are slim with little padding or recline capability. Since mid-2025, Spirit has introduced Go Comfy fare class seats near the front of the plane with four additional inches of legroom plus other perks like priority boarding. The Big Front Seats provide even more space at the front in a wider two-by-two arrangement.

Spirit's operations have been affected by ongoing Pratt & Whitney PW1100G engine issues that led to grounded planes due to manufacturing defects requiring lengthy inspections and repairs. This situation forced Spirit to cancel flights, reduce capacity, delay growth plans into at least 2026, and impacted revenue significantly as engine turnaround times sometimes exceed one year. Financially strained since posting losses starting in 2020—and after filing for Chapter 11 bankruptcy protection in November 2024—Spirit exited bankruptcy early in 2025 but warned it may not survive another year without new funding.

Avelo Airlines operates eight Boeing 737-700s and fourteen Boeing 737-800s but will begin receiving Embraer E195-E2 aircraft from 2027 onward for expanded service at smaller airports. Standard seat pitch is around 29 inches with a width of about 17 inches—slightly better than Spirit’s configuration. Avelo recently introduced Stretch (up to six extra inches of legroom) and Stretch+ (with blocked middle seat) options for added comfort.

When compared against major legacy airlines such as American Airlines (30–32 inch average seat pitch), Delta Air Lines (30–31 inch), and United Airlines (30–31 inch), ultra-low-cost carriers generally offer less space per passenger: Allegiant Air (28–30 inch), Frontier Airlines (28–29 inch), Spirit Airlines (28 inch), Avelo Airlines (29 inch).

According to the data reviewed, both Allegiant Air and Avelo Airlines provide similar average standard economy class seat pitches—around 29 inches—and allow passengers to purchase upgrades for more legroom if desired.

"However, taking into account Allegiant Air's more extensive route network, larger flight schedule, and variety of destinations served, this carrier seems to offer the best overall package."