For most travellers the Peak Design Travel Backpack is the best carry-on backpack: it is built to last, organised well and sold in three sizes. If you want to travel with one bag for weeks, the Tortuga Travel Backpack Pro 40L puts comfort first. The Tortuga Lite 40L is a lighter, cheaper option, and the BAGSMART Blast Pro 38L is the budget buy.
A good travel backpack is a bag you can carry for hours, fit in an overhead bin and pack and unpack without emptying it. This guide helps you choose among four options that approach that goal differently.
Key point
Backpack capacity is not the same as airline compliance. Airlines measure the bag, not the litres on the tag, and limits differ by carrier. Check your airline’s current carry-on size limit before you pack.
Our picks at a glance
| Product | Best for | Capacity | Price (Oct 2026, US list) |
|---|---|---|---|
| Peak Design Travel Backpack | Best overall | 20 L, 30 L or 45 L | 20 L from $199.95; 45 L about $299.95 |
| Tortuga Travel Backpack Pro 40L | One-bag trips | 40 L | $350 |
| Tortuga Travel Backpack Lite 40L | Lighter and cheaper | 40 L | $250 |
| BAGSMART Blast Pro 38L | Budget | 28 L expanding to 38 L | $89.99 |
Peak Design Travel Backpack: Best overall
The Peak Design Travel Backpack began life as the 45 L Travel Pack and is now a family in three sizes: 20 L, 30 L and 45 L. Peak Design describes the 20 L as a smaller, sharper version of the original, compact enough to be a personal item or a companion to a roller case, and expandable for spontaneous weekends.
What you pay for is design and durability: clean exterior lines, clever access, and a lifetime warranty. Peak Design’s own page lists the 20 L at $199.95, and the 45 L appears at about $299.95. Reviewers consistently praise the organisation and build quality, and they note that it is expensive.
Availability can fluctuate. During our checks some sizes and colours were out of stock, so confirm the size you want is in stock before you plan around it.
Choose the 45 L for week-long carry-on-only trips and the 20 L or 30 L when the pack is your personal item or a day bag.
Peak Design Travel Backpack
A premium expandable travel backpack available in 20 L, 30 L and 45 L sizes, with clamshell access and a lifetime warranty.
20 L from $199.95; 45 L about $299.95 (October 2026, US list price)
Tortuga Travel Backpack Pro 40L: Best for one-bag trips
Tortuga makes bags for exactly one use: travelling with a carry-on only. The Travel Backpack Pro 40L costs $350, and the maker describes it as a bag to fly carry-on-only on US and international airlines.
Its main selling points are comfort and access. Tortuga says up to 80% of the weight rides on your hips, not your shoulders, which is the main way to make a heavy pack comfortable over a long day. The suitcase-style opening means you can open it fully and see everything. It is also weatherproof, keeping clothes and a computer dry in any weather, according to the maker. It holds 7 to 10 days of clothes plus everything else you need.
It is a premium price for a pack, and a fully loaded 40-litre bag can be heavy. But if you plan to travel with one bag for a month, comfort matters more than the sticker price.
Tortuga Travel Backpack Pro 40L
A 40-litre carry-on travel backpack with a suitcase-style opening, hip-belt load carrying and weatherproofing.
$350 (October 2026, US list price)
Tortuga Travel Backpack Lite 40L: Best lighter Tortuga
The Tortuga Lite 40L is the simpler, cheaper sibling at $250. Tortuga says it meets US and international carry-on limits, fits 7 to 10 days of clothes and gear, and has a weight-bearing hip belt, a streamlined design with simpler organisation and a clamshell opening.
If you do not need the Pro’s extra features, the Lite gives you most of the benefit at $100 less. It is a good choice for travellers who like their bag light and uncomplicated and who pack tightly with cubes.
Tortuga Travel Backpack Lite 40L
A lighter, simpler 40-litre carry-on backpack with a weight-bearing hip belt and clamshell opening.
$250 (October 2026, US list price)
BAGSMART Blast Pro 38L: Best on a budget
The BAGSMART Blast Pro 38L is the budget pick at $89.99. It expands from 28 L to 38 L, which is useful if you want a compact bag for the flight out and extra room for the return. BAGSMART describes a flexible internal divider that keeps dirty shoes separate, tech compartments and stash pockets, and says it suits 3 to 5 day trips and fits most overhead bins.
It is not built for the same long-term abuse as Peak Design or Tortuga, and BAGSMART is a newer brand with a shorter track record. For occasional trips, it is the best way to try a carry-on backpack without a large outlay.
BAGSMART Blast Pro 38L Travel Backpack
A carry-on travel backpack that expands from 28 L to 38 L, with a flexible internal divider and tech compartments.
$89.99 (October 2026, US list price)
What to look for in a travel backpack
Capacity and expansion
For carry-on-only travel, 35 to 45 litres is the practical range. Bags at the top of that range can exceed some airlines’ limits when full. An expandable bag, such as the BAGSMART or the Peak Design, lets you shrink it for the flight and expand it on the way home.
Suitcase-style access
A clamshell or suitcase-style opening makes packing far easier than a top-loader, because you can see everything and use packing cubes. All four picks here offer that kind of access.
Harness and hip belt
If you carry the bag for more than 20 minutes at a time, a padded hip belt and an adjustable torso length matter more than any pocket. A hip belt transfers weight to your pelvis. The Tortuga packs highlight a weight-bearing hip belt.
Weather resistance
Look for water-resistant fabric and zips. No backpack is fully waterproof, so pack electronics in a pouch if you expect heavy rain.
Security
Lockable zips and hidden pockets deter pickpockets in crowded places. Keep your passport and cards in a body-facing pocket.
Weight when empty
A heavy pack uses up your weight allowance before you have packed anything. Compare empty weights if your airline has a cabin bag weight limit.
Backpack or suitcase?
| Situation | Better choice |
|---|---|
| Cobbled streets, stairs, trains, hostels | Backpack |
| Long, smooth airport corridors and hotels | Suitcase |
| Heavy loads over short distances | Suitcase |
| Hiking or off-road legs in the same trip | Backpack |
| Business trips with suits | Suitcase with a suiter, or a backpack with a garment fold |
A 40-litre backpack with a good hip belt gives you flexibility, but you carry the weight. If you have back or shoulder problems, a wheeled case may be kinder, and our guide to the best carry-on luggage compares four of them.
How to pack a travel backpack
- Start with a base layer of shoes in the bottom corners, heavy items close to your back.
- Use packing cubes for clothes, and keep a small one for tech.
- Put heavy items in the middle, close to your spine, so the weight sits over your hips.
- Keep your passport, charger and a layer within easy reach in a top or side pocket.
- Leave a little spare volume for souvenirs, or choose an expandable pack.
Tip
Weigh your packed bag at home. A fully loaded 40-litre pack can easily become heavy enough to be uncomfortable in a crowded station. If it is, remove items until it feels right for a 20-minute walk.
Choosing the right size
Size is the most common mistake. A bigger pack feels safer, but it fills with things you do not need and risks being refused as a carry-on.
| Pack size | Typical trip | Notes |
|---|---|---|
| 20 L | Day trips, a weekend, or a personal item | The Peak Design 20 L fits under most seats |
| 28 to 30 L | Long weekend to five days | The BAGSMART at its compact setting, or the Peak Design 30 L |
| 35 to 40 L | One week to ten days, carry-on only | The Tortuga packs sit here |
| 45 L | Longer trips, with disciplined packing | The Peak Design 45 L; watch airline limits |
If you will fly budget airlines with strict personal-item limits, a 20 L pack may be the only free bag you can bring, and a larger pack may need a paid cabin-bag allowance. Check the airline before you choose a size.
Who should skip each pack
- Peak Design: skip it if you want the lowest price, or if you need a specific size or colour that is out of stock.
- Tortuga Pro: skip it if you rarely do multi-week trips. At $350 it is a lot for weekend use.
- Tortuga Lite: skip it if you want lots of organisational pockets, since the design is deliberately simpler.
- BAGSMART: skip it if you want a bag that you expect to use heavily for many years.
A carry-on-only checklist
Travelling with a backpack works best when you plan around it. A few habits that help:
- Pick a colour palette. Clothes that mix and match need fewer items.
- Plan to launder. One load every week or so lets you carry far fewer clothes.
- Wear your bulkiest items. Boots and a jacket travel on your body, not in the bag.
- Decant toiletries. Use travel-sized bottles that fit your airline’s liquids rules.
- Keep a daily-use pouch. A small pouch for documents, headphones and a charger means you do not open the main compartment in transit.
- Leave 10% of the volume free. Souvenirs and wet clothes always take more space than expected.
Pairing a pack with packing cubes is the single biggest improvement you can make. A set of three cubes in a suitcase-style pack lets you remove a whole category of clothes in one go.
Which should you buy?
- Peak Design Travel Backpack if you want one pack that will last for years and can scale by size.
- Tortuga Pro 40L if you will live out of one bag for weeks.
- Tortuga Lite 40L if you want the same idea for $100 less.
- BAGSMART Blast Pro 38L if you want an inexpensive pack for occasional trips.
How we chose
We compared official specifications and pricing as of October 2026, alongside the consensus of established independent reviews. We shortlisted carry-on-sized packs with suitcase-style access, a clear warranty or return policy and a published price, and left out bags whose official pages did not list their capacity.
