Alaska Airlines allows one carry-on bag up to 22 x 14 x 9 inches plus one under-seat personal item, and they enforce these limits more strictly than many travelers expect. From my own flights, borderline hard-shell bags and anything over 22 inches often get pulled for sizing, while soft-sided bags that compress usually pass. If your carry-on is 22.5 inches or slightly over, expect case-by-case judgment and be prepared for a possible gate-check.
Alaska Airlines Carry-On Size
When I first started flying Alaska Airlines regularly, I assumed all airlines followed the same general carry-on rules. Then one morning at Seattle, I watched a gate agent pull several roller bags out of the boarding line, drop them into the metal sizer, and tag anything even slightly oversized for check-in.
One traveler’s suitcase was barely half an inch too tall, and it still had to be checked.
That moment made me finally take Alaska’s carry-on dimensions seriously.
This guide explains exactly how Alaska Airlines carry-on size works, how strict they are, and what happens if your bag is 1 inch too long, 22.5 inches, or a 24-inch suitcase. Everything is written from my first-person travel experience and years of real flights.
Alaska Airlines Carry-On Size (Official Rules)
Here is the exact carry-on size allowed on Alaska Airlines:
22 x 14 x 9 inches
(This measurement includes wheels and handles.)
You may also bring:
One personal item
This must fit completely under the seat, such as a backpack, purse, or laptop bag.
There is no official weight limit, but you must be able to lift your bag into the overhead bin yourself.
So Alaska’s carry-on allowance includes:
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Carry-on bag (overhead): 22″ x 14″ x 9″
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Personal item (under-seat): backpack, purse, laptop bag
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No weight limit, but you must lift the bag without assistance
My First Experience With Alaska’s Sizer
Years ago, I flew from Seattle to Anchorage with a suitcase labeled as 21 inches. When I measured it at home, the actual dimensions were:
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22.5 inches tall
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14 inches wide
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About 9.5 inches deep when full
At the gate, Alaska agents were actively checking bags in the metal sizer. Soft bags were squeezing in, but rigid hard-shell bags were not.
My suitcase barely fit because it was soft-sided. If it had been hard-shell, it would have been checked immediately.
That flight taught me an important lesson:
Alaska Airlines enforces carry-on size more strictly than many other US airlines.
Is Alaska Airlines Strict About Carry-On Size? My Honest Answer
After many years of flying Alaska, here is the truth:
Yes, Alaska Airlines can be strict, especially on busy flights.
They enforce size most heavily at:
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Seattle (SEA)
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Portland (PDX)
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Los Angeles (LAX)
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San Francisco (SFO)
During peak travel times, gate agents:
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Check bags visually while boarding
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Ask passengers to test borderline bags in the sizer
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Reject overstuffed or oversized hard-shell bags
So when people ask:
Is Alaska Airlines strict about carry-on size?
The realistic answer is yes. Expect enforcement of the 22 x 14 x 9 limit.
How I Pack to Always Pass Alaska’s Carry-On Rules
Here are the packing habits that have saved me from gate-check surprises:
1. Measure the bag yourself
Do not rely on the manufacturer’s label. Measure height, width, and depth with wheels and handles.
2. Avoid expansion zippers
Most suitcases expand to 10 or 11 inches thick. That breaks the 9-inch rule.
3. Prefer soft-sided luggage
Soft bags compress inside the sizer much better than rigid hard-shell bags.
4. Keep personal items slim
A slim laptop backpack fits under the seat without issues.
Carry-On and Backpack: What Alaska Actually Allows
I usually travel with:
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One 22-inch carry-on for the overhead bin
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One backpack that fits under the seat
Alaska allows this combination as long as the backpack fits fully under the seat and is not oversized. Large hiking backpacks may be counted as your carry-on instead.
Can a 24-Inch Suitcase Be a Carry-On on Alaska Airlines?
No. A 24-inch suitcase is too big.
The height limit is 22 inches, and a true 24-inch suitcase will almost never pass the sizer test. I have seen many passengers try, and every one of them had to check their bag.
If your suitcase is 24 inches, plan to check it.
What If My Carry-On Is 1 Inch Too Long?
This depends on the type of bag:
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Soft-sided 23-inch bags sometimes pass if they compress.
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Hard-shell 23-inch bags usually fail and must be checked.
If the bag cannot fit into the sizer, Alaska will not allow it as a carry-on.
What If My Carry-On Is 22.5 Inches?
I have flown with a 22.5-inch soft-sided bag before, and it fit only because:
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It was soft
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I packed lightly
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It compressed inside the sizer
22.5 inches is borderline.
A soft bag may pass. A hard-shell bag probably will not.
Does Alaska Airlines Check Bag Size at the Gate?
Yes, frequently.
Gate agents often:
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Ask passengers to test their carry-on in the sizer
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Reject bags that bulge or look oversized
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Enforce rules more strictly during full flights
If your bag appears too big, they will likely check it.
My Personal Carry-On Checklist for Alaska Airlines
Before every Alaska flight, I use this checklist:
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Measure the bag: exact size, including wheels
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Keep total size within 22 x 14 x 9 inches
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Never expand suitcase zippers
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Prefer soft-sided bags when close to the limit
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Keep under-seat items slim
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Do not overstuff front pockets
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Be prepared to check if the bag is obviously oversized
Using this approach, I have avoided carry-on issues for years.
Alaska Airlines Carry-On and Checked Bag Fees
Alaska Airlines does not charge for carry-on bags as long as they meet the size limit of 22 x 14 x 9 inches, but any oversized carry-on that fails the sizer test must be checked for a fee. For most passengers, the first checked bag costs about $35, the second costs about $45, and additional bags can be $150 or more. Overweight bags (51–100 lbs) typically incur a $100 surcharge, and oversize bags may cost around $150 extra, charged on top of the standard checked bag fee. Travelers in First Class, Mileage Plan elite members, and Alaska Airlines Visa credit card holders often receive one or more checked bags free, but all other passengers should expect to pay these standard rates.
Final Advice
If you want to avoid the stress of a last-minute gate-check, stick to the official Alaska Airlines carry-on size of 22 x 14 x 9 inches. Measure your bag at home and pack in a way that avoids bulging or expansion.