The 5 best underseat cabin bags from our range, by airline

The best underseat cabin bag in our range is the Overnighter: a 40 x 30 x 20 cm backpack that fits the free under-seat size of Ryanair, easyJet and Jet2, packs 45 litres with vacuum compression and takes a 16-inch laptop. If you fly British Airways, whose free hand bag is only 15 cm deep, our pick is a slim shoulder bag instead.

These are our own bags, chosen from our underseat bags and backpacks and the rest of our range, so we have made each drawback as visible as each strength. Below: how we chose, a comparison table, then the five picks.

• How we chose
• The five at a glance
• The five picks
• How to choose an underseat bag
• Frequently asked questions

How we chose

Amalia and the A&D team went through our catalogue on 6 November 2026: 256 bag models, of which 195 list all three dimensions on their product page. We kept bags made for a flight or able to replace one: the four distinct models of our underseat collection, plus one everyday bag for the strictest airline.

Every size in this article comes from our product pages. We then checked each bag, longest side against longest side, against the free under-seat allowance of four airlines, read on their own websites on 6 November 2026:

• Ryanair: one small personal bag of 40 x 30 x 20 cm on every fare, according to Ryanair's bag policy;
• easyJet: one small under-seat bag of 45 x 36 x 20 cm, handles and wheels included;
• Jet2: one small under-seat bag of 40 x 30 x 20 cm, alongside the included 10kg bag;
• British Airways: one hand bag of 40 x 30 x 15 cm, alongside the cabin bag.

We have not flown with these bags for this article, and no bag is guaranteed to pass a gate check: a soft bag measured empty can grow once packed.

The five at a glance

Bag	Best for	Fits	Dimensions (cm)	Material
Overnighter	Ryanair, easyJet and Jet2 trips of a few days	16-inch laptop, 45 L compressed	40 x 30 x 20	Oxford cloth
Daily	A lighter-packed short trip on the same airlines	15-inch laptop, 35 L compressed	40 x 30 x 20	Nylon
Commuter	Work trips with a laptop or tablet	15-inch laptop, tablet, 35 L compressed	40 x 20 x 25	Nylon
Weekender	easyJet, when you want suitcase-style access	16-inch laptop, 45 L	45 x 36 x 20	Oxford, polyester lining
Urbino	British Airways, and every airline above	15-inch laptop, water bottle, A4	40 x 29 x 12	Vegan leather

Airline sizes checked 6 November 2026 on each airline's website. Allowances change; check your booking before you fly.

The five picks

1. The Overnighter: our top pick

The Overnighter is the most complete underseat bag we sell for the three airlines with a 20 cm-deep free bag.

• Size: 40 x 30 x 20 cm, within Ryanair's and Jet2's 40 x 30 x 20 cm and easyJet's 45 x 36 x 20 cm.
• Capacity: 45 litres using vacuum compression, plus a 5 cm expansion.
• Laptop: dedicated 16-inch compartment.
• Inside: dry and wet separation, a key holder and zipped pockets.
• Extras: built-in USB charging port and a TSA-approved lock.
• Material: Oxford cloth; also made in a pink edition.

Best for: three to four days away on Ryanair, easyJet or Jet2 without paying for an overhead bag.

Worth knowing: the 45 litres only fit once compressed, and 40 x 30 x 20 cm is already Ryanair's and Jet2's exact limit, so any use of the 5 cm expansion takes it past them. On easyJet it depends on which side expands, which the product page does not say, so keep it closed for the flight. At 20 cm deep, it is a cabin bag, not the hand bag, on British Airways.

2. The Daily: best for lighter packing

The Daily keeps the Overnighter's footprint with a simpler build and less to carry.

• Size: 40 x 30 x 20 cm, the full Ryanair and Jet2 free size.
• Capacity: 35 litres with built-in vacuum compression.
• Packing: 2 to 4 days of outfits, according to the product page.
• Laptop: reinforced laptop compartment, listed for a 15-inch laptop.
• Straps: air cushion shoulder straps.
• Material: nylon.

Best for: a weekend or a short work trip where clothes matter more than gadgets.

Worth knowing: it has 10 litres less than the Overnighter, and none of the Overnighter's extras: no expansion, no TSA lock and no USB port. Its product page lists a 15-inch laptop, so a 16-inch one needs the Overnighter. Like the Overnighter, it is too deep for BA's 15 cm hand bag.

3. The Commuter: best for laptop days

The Commuter is the most compact of our travel backpacks, designed around a laptop and tablet slot.

• Size: 40 x 20 x 25 cm, within Ryanair's, Jet2's and easyJet's free sizes.
• Capacity: 35 litres using vacuum compression.
• Laptop: dedicated laptop and tablet slot, listed for a 15-inch laptop.
• Packing: 2 to 4 days of outfits, according to our catalogue.
• Material: nylon.

Best for: a work trip where you need your laptop at security and on arrival.

Worth knowing: its product page lists a 15-inch laptop, so a 16-inch laptop is not covered; for that, the Overnighter is the one. Its smallest side is 20 cm, which still rules it out as BA's hand bag.

4. The Weekender: best for easyJet

The Weekender uses every centimetre of easyJet's more generous free bag.

• Size: 45 x 36 x 20 cm, exactly easyJet's free under-seat size.
• Capacity: 45 litres, with vacuum compression and a 5 cm expansion.
• Opening: 180-degree, suitcase-style, so nothing hides at the bottom.
• Laptop: 16-inch slot.
• Security: a rear zipped pocket for documents, cards and keys.
• Material: Oxford outer with a polyester lining.

Best for: easyJet weekends where you want to open the bag like a suitcase.

Worth knowing: at 45 x 36 cm it is too big for the free bag on Ryanair, Jet2 and British Airways, and it has no margin at all on easyJet. Any expansion takes it past easyJet's limit.

5. The Urbino: best for British Airways

The Urbino is an everyday shoulder bag that happens to be the only pick within all four airlines' free sizes.

• Size: 40 x 29 x 12 cm, within BA's 40 x 30 x 15 cm hand bag.
• Fits: a 15-inch laptop, a water bottle and A4 documents.
• Inside: slot pocket, phone pocket and zip pocket.
• Carry: shoulder.
• Material: vegan leather with a polyester lining.

Best for: British Airways, where the hand bag holds your laptop, documents and medicine while the cabin bag goes overhead.

Worth knowing: it is a handbag, not a travel bag: no compression, no luggage strap and no room for several days of clothes. On BA it works because the 56 x 45 x 25 cm cabin bag carries the rest.

How to choose an underseat bag

Start with your strictest airline

Under-seat sizes vary more than overhead sizes. easyJet allows 45 x 36 x 20 cm, Ryanair and Jet2 40 x 30 x 20 cm, and British Airways 40 x 30 x 15 cm for its hand bag. If you fly several airlines in a year, buy for the smallest allowance you use, and remember that BA's limit is on depth.

Measure packed, not empty

A soft backpack grows as you fill it, and expansion zips add centimetres. Compression helps you fit more in, but the bag still has to match the airline's size once packed. Measure with a tape measure the night before, including any handles and wheels.

Decide where the laptop lives

On BA and Jet2, a larger cabin bag may be moved to the hold on a busy flight, so laptops, chargers and medicine belong in the under-seat bag. Check the laptop size on the product page: the Overnighter and Weekender list 16 inches; the Daily, the Commuter and the Urbino 15 inches.

Frequently asked questions

What size bag fits under most airline seats?

There is no single size, but 40 x 30 x 20 cm is the free under-seat size on Ryanair and Jet2 and sits within easyJet's 45 x 36 x 20 cm, according to their websites on 6 November 2026. British Airways is stricter on depth, at 40 x 30 x 15 cm for its hand bag.

Which airline has the smallest underseat bag?

Of the four airlines we checked on 6 November 2026, British Airways has the shallowest free under-seat bag, at 40 x 30 x 15 cm. Ryanair and Jet2 allow 40 x 30 x 20 cm and easyJet 45 x 36 x 20 cm. BA, however, also includes a 56 x 45 x 25 cm cabin bag on every fare.

Are underseat cabin bags worth it?

An underseat cabin bag is worth it if you fly airlines that charge for an overhead bag, such as Ryanair and easyJet, and can travel light. A 40 x 30 x 20 cm bag counts as the free bag on both. If your airline already includes a large cabin bag, a slim handbag may serve you better.

Can a backpack be an underseat bag?

Yes, if it is within the airline's size. Ryanair names a handbag or laptop bag as examples, but what counts is the measurement: 40 x 30 x 20 cm on Ryanair, 45 x 36 x 20 cm on easyJet. The backpack must fit under the seat in front of you.

Our verdict, by traveller

If you fly Ryanair, Jet2 or easyJet for a few days, the Overnighter does the most in the free size. If you pack lightly, the Daily does the same job with less bag. If your laptop matters more than your wardrobe, the Commuter. If you only fly easyJet, the Weekender uses every centimetre. If you fly British Airways, take the Urbino under the seat and let the cabin bag do the rest. For the full Ryanair rules, including the paid 10kg bag, see our guide to the Ryanair cabin bag size.