The TSA rules for carry-on items

The Transportation Security Administration (TSA) sets the rules for what goes in your carry-on bag on flights within and from the United States. The basic rule is straightforward: you can bring almost anything that is not a weapon, explosive, or flammable — but liquids, gels, and aerosols have strict limits. Solid items almost never have restrictions, which is why most of your clothing, books, electronics, and toiletries can travel with you in the cabin.

The TSA does not ban items outright based on what they are — they ban them based on how they behave. A lighter is banned because it can ignite. A bottle of shampoo is not banned, but only 3.4 ounces of it can go in your carry-on because larger quantities of liquid pose a fire risk in pressurized cargo holds. Understanding this distinction helps you pack smarter and avoid surprises at security.

Key Takeaways

  • Liquids, gels, and aerosols in carry-on bags must each be 3.4 ounces or smaller and fit inside a single quart-sized clear plastic bag.
  • Solid items — clothing, shoes, books, electronics, toiletries in solid form — have no size or quantity limits in carry-on bags.
  • Common items that seem harmless, like lighters, certain tools, and some sports equipment, are actually prohibited in carry-on bags but may be allowed in checked luggage.
  • The TSA website has a searchable tool called "What Can I Bring?" where you can type any item and see the current rule for that specific thing.
  • Airport security officers have final authority to decide whether an item can board, even if the TSA website says it is allowed.

The 3-1-1 rule for liquids and gels

The 3-1-1 rule is the core of TSA liquid restrictions: 3.4 ounces per container, 1 quart-sized clear plastic bag, 1 bag per passenger. Each container must be 3.4 ounces (100 milliliters) or smaller. The bag itself must be transparent and roughly the size of a quart of milk — the TSA does not measure it precisely, but gallon bags are too large and sandwich bags are too small. You get one bag, and it must fit in the security bin during screening.

This rule applies to anything that flows, spreads, or sprays: shampoo, conditioner, lotion, sunscreen, toothpaste, peanut butter, yogurt, honey, jam, and aerosol deodorant. Solid deodorant is fine in any quantity. Mascara, liquid eyeliner, and foundation count as liquids. Lipstick does not. If you are unsure whether something is a liquid or a gel, the safest approach is to pack it in your checked bag or buy a travel-size version after you pass security.

Electronics and batteries in carry-on bags

Laptops, tablets, phones, cameras, and headphones all travel in carry-on bags without restriction. You will remove your laptop and place it in a separate bin during security screening, but there is no limit on how many electronic devices you can bring. Power banks and portable chargers are allowed, but they must stay in your carry-on bag — they cannot go in checked luggage because of fire risk in the cargo hold.

Spare batteries have specific rules. Lithium-ion batteries (the kind in phones and laptops) are allowed in carry-on bags in reasonable quantities — the TSA does not set a hard number, but a few spares for personal use are fine. Lithium metal batteries are more restricted: you can bring no more than two spares, and they must be in your carry-on bag, not checked luggage. If you are traveling with specialty batteries for cameras or medical devices, check the TSA website or call ahead to confirm the limit.

Tools, sports gear, and other restricted items

Many items that seem harmless are actually prohibited in carry-on bags because they could be used as weapons. A box cutter, utility knife, or razor blade cannot go in your carry-on, even though you might use it to open packages at home. Scissors are allowed only if the blades are shorter than 4 inches and the handles are blunt. A hammer, wrench, or screwdriver longer than 7 inches is prohibited in carry-on but may be allowed in checked luggage.

Sports equipment rules vary by item. Baseball bats, cricket bats, and hockey sticks cannot go in carry-on bags but are usually allowed in checked luggage. Golf clubs are allowed in checked bags. Ski poles, ski boots, and skis are allowed in checked bags. A tennis racket or badminton racket is allowed in carry-on. Firearms, ammunition, and realistic replica guns are never allowed in carry-on bags and have strict rules for checked luggage — you must declare them to the airline before you arrive at the airport.

Medications, medical devices, and personal care items

Prescription and over-the-counter medications in pill, capsule, or tablet form have no restrictions in carry-on bags. You do not need to declare them or show a prescription, though it is a good idea to keep medications in their original labeled bottles. Liquid medications like cough syrup or insulin are allowed in carry-on bags in reasonable quantities — you do not have to follow the 3.4-ounce limit for medically necessary liquids, but you should declare them to security and be prepared to explain what they are.

Medical devices like CPAP machines, nebulizers, and oxygen concentrators are allowed in carry-on bags. Syringes and lancets for diabetes management are allowed if they are accompanied by insulin or other injectable medication. Gel ice packs used to keep medications cool are allowed if they are completely frozen solid at the time of screening — if they have any liquid, they count as a liquid and must follow the 3.4-ounce rule. Solid deodorant, toothpaste in solid form, and other solid toiletries have no restrictions.

Food, beverages, and perishables

Solid foods like sandwiches, fruit, cheese, and cookies are allowed in carry-on bags in any quantity. You can bring a full meal if you want. Peanut butter, jam, honey, and other spreads are liquids or gels under TSA rules, so they must be 3.4 ounces or smaller and fit in your quart-sized bag. Yogurt, pudding, and other creamy foods are also liquids and subject to the same limit.

Beverages cannot go through security in your carry-on bag — you cannot bring a bottle of juice, soda, or water through the checkpoint. You can buy drinks after you pass security and bring them on the plane. Alcohol is allowed in carry-on bags only if it is 70 proof or lower and in containers of 3.4 ounces or smaller, which makes it impractical for most people. Frozen foods are allowed if they are completely solid at the time of screening, but if they begin to thaw and become slushy, they may be treated as a liquid.

Items that vary by airline or airport

Some items are allowed by TSA rules but may be restricted by individual airlines. Vaping devices and e-cigarettes are allowed by TSA in carry-on bags only — they cannot go in checked luggage because of battery fire risk. However, some airlines prohibit them entirely, so check your airline's website before you pack. Lighters are prohibited in both carry-on and checked bags on most airlines, though some allow one lighter in checked luggage if it is in a protective case.

Airport security officers have the final say on what boards the plane. Even if the TSA website says an item is allowed, a security officer can decide it poses a risk and prevent it from going through. If this happens, you can ask to speak with a supervisor, but the decision is final. The best approach is to use the TSA's "What Can I Bring?" tool on their website — you can search for any specific item and see the current rule, and many items have photos or detailed explanations.

Frequently Asked Questions

Can I bring a full-size bottle of shampoo if I check my bag?

Yes. The 3.4-ounce limit applies only to carry-on bags. Checked luggage has no restrictions on liquids, gels, or aerosols — you can pack full-size bottles of shampoo, lotion, perfume, and other liquids. However, if your bag is damaged or lost, those items may not be covered by the airline's liability limits, so consider packing expensive or irreplaceable liquids in your carry-on instead.

What if I have a lighter I need for camping or a candle?

Lighters are prohibited in both carry-on and checked bags on flights within the United States. If you need a lighter at your destination, buy one after you arrive. Some airlines allow one lighter in checked luggage if it is in a protective case and you declare it, but this varies by carrier — call your airline before you pack to confirm their specific rule.

Can I bring my laptop charger and power bank on the plane?

Yes. Laptop chargers and power banks are allowed in carry-on bags. Power banks must stay in your carry-on bag, not checked luggage, because of the lithium-ion battery inside. There is no limit on how many chargers or power banks you can bring, as long as they fit in your bag.

Are gel insoles or gel eye masks allowed in carry-on?

Gel insoles and gel eye masks are allowed in carry-on bags as long as they are completely solid — not squishy or partially liquid. If they have any liquid component or feel slushy, they may be treated as a gel and subject to the 3.4-ounce limit. When in doubt, pack them in your checked bag or ask security before screening.

What is the best way to know if a specific item is allowed?

Use the TSA's "What Can I Bring?" tool on their website — search for the item by name and you will see whether it is allowed in carry-on, checked, or both. The tool includes photos and explanations for most common items. If you cannot find your item or the answer is unclear, contact the TSA directly through their website or call your airline before you travel.