domestic · 4h 00m · 2,960 km
Houston to Seattle
2 airlines · 2 aircraft ranked
In economy, Alaska's Main Cabin (737-900ER) edges out the field with a 4.4/10.In first class, United's United First (737-900ER) edges out the field with a 2.8/10.
Quick pick
Fly Alaska. It scores higher across seat comfort and amenities.
If prices are similar, go with this one.
Fly United. It scores higher across seat comfort and amenities.
If fares are comparable, this is the better cabin.
Select two airlines to compare head-to-head
Data verified June 2026
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Route insights
- In economy, Alaska's Main Cabin (737-900ER) edges out the field with a 4.4/10.
- In first class, United's United First (737-900ER) edges out the field with a 2.8/10.
Frequently asked
Which is better in first: United or Alaska on IAH-SEA?
United First (United Airlines, 737-900ER) and First Class (Alaska Airlines, 737-900ER) score virtually the same in first: 2.8 vs 2.8/10. The biggest gap is seat width — 21"-wide seats vs 20" — but neither carrier pulls ahead overall.
Which is better in economy: United or Alaska on IAH-SEA?
Economy (United Airlines, 737-900ER) and Main Cabin (Alaska Airlines, 737-900ER) score virtually the same in economy: 4.2 vs 4.4/10. The biggest gap is power — AC + USB-C vs USB-C only — but neither carrier pulls ahead overall.
What are the best seats in United United First on IAH-SEA?
Best: Row 1 has the most legroom as a bulkhead. 1A and 1F offer the most privacy with the wall on one side. Row 2 is the sweet spot between legroom and storage (bulkhead rows lack under-seat storage). Avoid: Row 5 seats 5A/5B do not recline; 5E/5F have roughly half the recline of other First rows. This is the biggest seat trap on the 737-900ER. Signature Interior with Collins Aerospace Pinnacle seats, 13-inch HD seatback touchscreens with Bluetooth audio, USB-A and USB-C at every seat plus AC outlet. Complimentary meal service on flights over 800 miles; snack basket on shorter flights. ViaSat Ka-band WiFi free for MileagePlus members. Starlink awaiting FAA certification for 737-900ER, expected during 2026. Majority of fleet retrofitted to Signature Interior; some older aircraft remain.
What are the best seats in United Economy on IAH-SEA?
Best: Exit row 21 has 38.8 inches of pitch — more than First Class. The 2-seat side rows 20-21 are the best economy seats on the plane. Rows 7-14 are Economy Plus with 33-34-inch pitch. Avoid: Last row (row 33) has severely limited or no recline due to the rear lavatory wall. Rows 32-33 experience galley noise and lavatory traffic. Middle seats (B, E) in any row are the tightest at 30-inch pitch. Signature Interior with 10-inch HD seatback touchscreens and Bluetooth audio. USB-A and USB-C at every seat plus shared AC outlets. ViaSat Ka-band WiFi free for MileagePlus members. 42 Economy Plus seats in rows 7-14 have 33-34-inch pitch; 117 standard Economy seats have 30-inch pitch. Three sub-variants exist (39/42/45 Economy Plus seats); Version 2 with 42 E+ is most common (~84 of ~99 aircraft).
What are the best seats in Alaska First Class on IAH-SEA?
Best: Row 1 for maximum legroom. Window seats in rows 1-2 are quiet and private. Avoid: Row 4 (last row of first) may have limited meal choices due to service order. 41-inch pitch is among the best domestic first class products in the US. No seatback IFE screens; stream to personal devices via Gogo 2Ku Wi-Fi. USB-A and AC outlet under center armrest. Free for T-Mobile customers. Pre-order meals system with limited choices.
What are the best seats in Alaska Main Cabin on IAH-SEA?
Best: Exit row seats (row 15/16) offer extra legroom. Avoid: Last row (34) has limited recline and is near the lavatory. Middle seats throughout. Standard domestic economy with 31-inch pitch. USB-A and AC power at every seat. No seatback screens; entertainment streams to personal devices. Boeing Sky Interior with larger overhead bins. Exit row seats on the 737 offer extra legroom but do not recline. The row immediately before the exit also has limited recline due to clearance requirements.