What the TSA allows in carry-on luggage
The TSA (Transportation Security Administration) lets you bring most everyday items in your carry-on bag, but there are hard rules about liquids, sharp objects, and anything that could be used as a weapon. You can pack clothing, books, electronics, toiletries in solid form, and most personal items without restriction. The main limit is the 3-1-1 rule for liquids: containers of 3.4 ounces (100 milliliters) or smaller, all fitting in one quart-sized clear plastic bag, one bag per passenger.
What you cannot bring includes anything flammable (lighters, aerosols), weapons (knives, guns, tools over 7 inches), and liquids or gels over the size limit. Ice packs and frozen items are allowed only if completely solid when you reach the checkpoint — if they have any liquid, they count as a liquid. The rules are the same whether you fly domestic or international from a U.S. airport, though some countries have stricter rules for what you can bring into that country.
Key Takeaways
- Liquids, gels, and creams must be 3.4 ounces or smaller and fit in one quart-sized clear bag; this includes shampoo, lotion, peanut butter, and yogurt.
- Sharp objects like knives, razors, and scissors are not allowed; nail clippers and files are permitted only if the blade is under 6 centimeters.
- Electronics including laptops, phones, and tablets are allowed and do not count toward your liquid limit.
- Solid food items like sandwiches, fruit, and cookies are allowed; anything spreadable or in a container counts as a liquid or gel.
- Check your airline's carry-on size limits before packing, because TSA approval does not mean the bag will fit in the overhead bin.
The 3-1-1 liquid rule explained
The 3-1-1 rule is the single most important thing to remember: 3.4 ounces per container, 1 quart-sized bag, 1 bag per person. This applies to anything that flows, spreads, or sprays — not just water. Shampoo, conditioner, lotion, sunscreen, deodorant, toothpaste, peanut butter, jam, honey, yogurt, and mascara all count. Even a half-full bottle of lotion counts as a liquid container, so the size of what is inside does not matter, only the size of the container itself.
You must place all containers in a single clear plastic bag about the size of a quart of milk. You can buy these bags at any drugstore, or the TSA will provide one at the checkpoint if you forgot. Medications and baby formula are exempt from the 3.4-ounce limit, but you should still pack them in a separate bag and tell the TSA officer about them. Solid items like deodorant sticks, lip balm, and bar soap do not count as liquids and can go anywhere in your carry-on.
Items you cannot bring in carry-on luggage
Weapons and anything that resembles a weapon are banned. This includes knives of any length, box cutters, ice picks, and tools like hammers and wrenches. Firearms, ammunition, and explosives are absolutely prohibited. Flammable items such as lighters, matches, aerosol cans (hairspray, spray paint, bug spray), and self-inflating life jackets cannot go in carry-on or checked bags on most airlines.
Sharp objects have specific rules: scissors are allowed only if the blades are under 6 centimeters (about 2.4 inches) from the pivot point. Nail clippers and metal nail files are permitted. Straight razors and safety razors are not allowed in carry-on but may be packed in checked luggage. Sporting equipment like baseball bats, ski poles, and hockey sticks are prohibited in carry-on but often allowed in checked bags — check with your airline first.
Certain electronics are restricted. You cannot bring a power bank larger than 100 watt-hours without airline permission, and anything over 160 watt-hours is banned entirely. Laptops, phones, tablets, and cameras are fine. Lithium batteries (the kind in electronics) have strict rules: you can bring two spare batteries in carry-on if they are in their original packaging or have the terminals taped to prevent short circuits.
Food and beverages you can pack
Solid foods pass through security with no problem. You can bring sandwiches, fruit, vegetables, cookies, granola bars, nuts, cheese, and chocolate. Anything that is solid at room temperature is allowed. The restriction is on anything spreadable or in liquid form: peanut butter, jam, honey, yogurt, peanut sauce, and hummus must follow the 3-1-1 liquid rule if you want to bring them.
Beverages cannot pass through security. You cannot bring a bottle of water, juice, coffee, or any liquid drink through the checkpoint, even if it is sealed. You can buy drinks after you clear security and bring them on the plane. Some airports have water fountains near the gates where you can fill a reusable bottle after security. Frozen items like ice cream or a frozen water bottle are allowed only if completely solid when you reach the checkpoint — if there is any liquid or slush, it will be confiscated.
Electronics and chargers in carry-on bags
All common electronics are allowed: laptops, tablets, e-readers, phones, cameras, headphones, and portable speakers. You do not need to remove them from your bag at security unless the TSA officer asks. Chargers and charging cables have no restrictions. Power banks are allowed as long as they are under 100 watt-hours; most standard phone chargers and portable batteries fall well below this limit.
Lithium batteries require care. You can bring up to two spare lithium batteries in carry-on luggage if they are installed in a device (like a phone or laptop) or if they are loose in their original retail packaging. If you are bringing loose batteries, tape the terminals (the metal contacts) with non-conductive tape to prevent accidental short circuits. Batteries in checked luggage have different rules — check with your airline before packing spares in your checked bag.
Medications, medical devices, and personal care items
Prescription and over-the-counter medications in pill, capsule, or tablet form have no restrictions and do not count toward your liquid limit. Liquid medications like cough syrup or insulin are exempt from the 3.4-ounce rule, but you should pack them separately and inform the TSA officer at the checkpoint. Bring medications in their original labeled containers so there is no question about what they are.
Medical devices such as inhalers, EpiPens, and glucose meters are allowed. Syringes are permitted if they are accompanied by medication or a medical device. If you use a CPAP machine or other medical equipment, you can bring it in carry-on. Deodorant sticks, solid perfume, and bar soap are allowed without restriction. Razors (safety razors and cartridge razors) are allowed in carry-on, but straight razors must go in checked luggage.
Checking your airline's specific rules
TSA rules explore to all U.S. airlines, but individual airlines set their own carry-on size and weight limits. A bag that passes TSA screening might still be too large for the overhead bin on a regional jet. Most airlines allow one personal item (purse, backpack, laptop bag) plus one standard carry-on roller bag. Some budget airlines charge for a second carry-on or have stricter size limits, so check your airline's website before you pack.
International flights have the same TSA rules for leaving the United States, but the country you are flying to may have different rules. Some countries restrict certain foods, medications, or electronics. If you are flying internationally, check the customs and immigration rules for your destination country at least a week before your trip. Your airline's website usually has a link to country-specific restrictions, or you can contact the embassy of the country you are visiting.
Frequently Asked Questions
Can I bring a full-size bottle of shampoo if I only use a little bit?
No. The TSA measures the container size, not how much liquid is inside. A full bottle and a half-empty bottle are treated the same way. If the container is larger than 3.4 ounces, it cannot go in carry-on. You can pack a full-size bottle in your checked luggage instead, or buy travel-size bottles at a drugstore.
Are gel deodorants allowed in carry-on?
Gel deodorants count as a liquid or gel and must follow the 3-1-1 rule. Solid stick deodorants do not count as a liquid and can go anywhere in your carry-on. If you use gel deodorant, pack a 3.4-ounce container or smaller in your quart-sized bag, or switch to a stick for travel.
Can I bring a lighter or matches on a plane?
No. Lighters and matches are prohibited in both carry-on and checked luggage on commercial flights. This is a federal rule that applies to all airlines. If you smoke, you will need to wait until you land and are outside the airport.
What happens if I accidentally bring a banned item to security?
The TSA officer will confiscate it. You can ask them to hold it at the checkpoint, mail it to your home, or throw it away. If you have time before your flight, you can also leave the security area, go back to the ticket counter or a shop, and mail the item to yourself. There is usually no fine for accidentally bringing a prohibited item.
Can I bring a power bank larger than 100 watt-hours if I ask the airline first?
Some airlines allow power banks between 100 and 160 watt-hours with advance permission, but this varies by airline. Contact your airline before your trip if you have a large power bank. Anything over 160 watt-hours is banned on all commercial flights, even with permission.