Fly standby
like you mean it.

The goal: surface routes with the most open seats for non-revenue standby. Three things drive that — low load factor (more empty seats), high frequency (more daily flights to try), and aircraft gauge (a 300-seat 787 has way more standby room than a 76-seat E175). The Standby Index blends emptiness and frequency (≈55% / 45%); a parallel Seats / week sort surfaces the gauge dimension — a daily 787-9 to London beats 3× daily E175 to Wenatchee on raw seat volume, even though both fly seven days a week.

What's hard data vs. an estimate

• ✓ DOT-measured — Alaska's 2025 systemwide load was 82.9% (83.6% excluding intra-Alaska flying), per U.S. DOT data. A handful of route-level loads are also public: SEA–Vail/Eagle ran just 39.4% full in 2025 (the emptiest route Alaska flies), and the Seattle–Tokyo / Seattle–Seoul long-hauls report monthly DOT loads.
• ~ estimated — Clean Alaska-only, route-level passenger+seat data for the big year-round routes is not publicly extractable without a direct BTS TranStats query. Those load factors are estimated from the ~83% system benchmark, nudged by route type (leisure transcon and Hawaii skew higher; midweek/shoulder skews lower). Treat them as directional, not gospel.

Frequency & gauge figures

Monthly flight counts come from a mix of Cirium scheduled capacity (Spring 2025 snapshot, the older mainline routes) and May 2026 published schedules (Expedia / FlightsFrom / press releases — the recent additions and corrections). Both are flagged ~ est for honesty. Seat counts per aircraft type are tool-internal assumptions: E175 = 76, 737-800 / MAX 8 = 159, 737-900 / MAX 9 = 178, A330-200 = 278, 787-9 = 300; mixed-fleet routes (e.g. SEA–HNL: Alaska 737 + Hawaiian A330) use a weighted blend.

What's in scope

Every nonstop from SEA operated on Alaska Air Group metal: mainline Boeing 737 and Boeing 787-9 (carrier AS), Horizon Air E175 regional (QX, the wholly-owned subsidiary), SkyWest E175 flown as Alaska under a capacity-purchase agreement (OO), and post-merger Hawaiian widebodies — A330 and 787-9 (HA, code retiring through 2026) — including SEA–NRT, SEA–ICN, and the Hawaiian frequencies on SEA–HNL and summer SEA–ANC. SEA is now Alaska's 787-9 international base: London (LHR) and Rome (FCO) launched in 2026 on Alaska's own 787-9s, with the Asian long-hauls flown by Hawaiian's. We exclude partner and codeshare flying — routes Alaska sells a seat on but doesn't operate (American/oneworld, Avelo, JSX, etc.) — because standby benefits don't travel cleanly across those. Use the Fleet chip row to slice the map by Mainline / Regional / Sub-regional. Operator (QX vs OO vs HA) shows in each route's drawer because jumpseat/non-rev rules differ. Borderline cities (e.g. Spokane, San Jose) mix fleets; check the operating aircraft before counting on it.

The caveat that matters most for standby

Load factor counts paying passengers only. Real day-of availability also depends on the non-rev priority list, crew and positioning needs, and weight & balance — a 70%-full flight can still zero out for standby if the list is deep. The math hits harder on regionals: a 76-seat E175 zeroes out far faster than a 159-seat 737 even when the load number looks light, so weight regional emptiness with that in mind. Always check the live seat-available and standby counts in the employee travel tools the day you fly. Schedules and fleet assignments are also shifting through 2026 as the Alaska–Hawaiian integration completes.