The TSA rules for carry-on items

The Transportation Security Administration (TSA) allows most everyday items in your carry-on bag, but a few categories are restricted or banned entirely. You can bring clothing, books, electronics, toiletries under 3.4 ounces, and most food items. You cannot bring weapons, sharp objects longer than 7 inches, flammable liquids, or anything the TSA considers a security risk.

The rules are the same whether you fly domestic or international from a U.S. airport. If you are connecting through another country or flying from abroad, that country's rules may differ — check with your airline or the airport authority before you pack.

Size and weight limits for carry-on bags themselves vary by airline. Most allow one personal item (purse, laptop bag, small backpack) plus one standard carry-on roller bag, typically 22 by 14 by 9 inches. Check your airline's website for exact dimensions, because oversized bags get checked at the gate and you lose access to them during the flight.

Key Takeaways

  • Liquids and gels in carry-on bags must be 3.4 ounces or smaller and fit in a single quart-sized clear bag.
  • Sharp objects like knives, razors, and scissors are banned from carry-on but allowed in checked luggage.
  • Electronics including laptops, phones, and tablets are allowed and must be removed at security screening.
  • Medications in original containers and medical devices like inhalers and EpiPens are permitted in carry-on bags.
  • Lighters, flammable liquids, and tools longer than 7 inches are prohibited in both carry-on and checked bags.

Liquids, gels, and the 3.4-ounce rule

Any substance that flows or spreads — including shampoo, conditioner, lotion, toothpaste, peanut butter, yogurt, and jam — counts as a liquid or gel for TSA purposes. Each container must be 3.4 ounces (100 milliliters) or smaller. All containers together must fit inside a single quart-sized clear plastic bag, which you remove at security and place in the bin with your shoes and belt.

Solid items like deodorant sticks, bar soap, and solid perfume are not restricted by the 3.4-ounce rule, though they still go through the scanner. Aerosols like hairspray and spray deodorant count as liquids and follow the same 3.4-ounce limit.

If you need more than 3.4 ounces of a liquid or gel, pack it in your checked bag instead. Checked luggage has no liquid restrictions. Many travelers buy travel-sized bottles at drugstores or use refillable containers to stay under the limit.

Electronics and chargers

Laptops, tablets, e-readers, phones, cameras, and portable chargers are all allowed in carry-on bags. You must remove laptops and large electronics from your bag at security screening and place them in a separate bin so they can be X-rayed alone. Smaller items like phones and earbuds can stay in your bag.

Chargers and charging cables have no restrictions. Power banks and portable battery packs are allowed, but lithium batteries over 100 watt-hours are prohibited. Most standard portable chargers sold for phones and tablets are under this limit — check the label or the manufacturer's website if you are unsure.

Do not pack spare lithium batteries (the kind used in cameras or laptops) in carry-on or checked bags unless they are installed in a device. These batteries are considered hazardous and are banned from passenger aircraft.

Sharp objects and tools

Knives of any size, razors, box cutters, and scissors with blades longer than 7 inches are banned from carry-on bags. Scissors under 7 inches with rounded tips are allowed. Nail clippers, tweezers, and small multi-tools without blades are permitted.

If you need a knife or razor for your trip, pack it in your checked bag. Checked luggage has no restrictions on sharp objects. Many travelers forget this rule and arrive at security with a knife in their carry-on, forcing them to throw it away or check their bag at the last minute.

Tools like screwdrivers, hammers, and wrenches are prohibited in carry-on if they are longer than 7 inches or could be used as a weapon. Smaller tools may be allowed — the TSA website has a searchable tool where you can look up specific items.

Medications and medical devices

Prescription and over-the-counter medications in their original labeled containers are allowed in carry-on bags with no quantity limit. You do not need a doctor's note or special documentation for common medications like ibuprofen, allergy pills, or antacids.

Medical devices like inhalers, EpiPens, insulin pens, and nebulizers are permitted. If you use an insulin pump or continuous glucose monitor, inform the TSA officer at security — they may need to inspect it separately, but you will not be asked to remove it.

Liquid medications like cough syrup or liquid antibiotics are subject to the 3.4-ounce liquid rule unless you declare them as medications. Tell the TSA officer that you are carrying liquid medication, and they may allow you to carry more than 3.4 ounces. Keep medications in their original containers with your name on the label.

Food and beverages

Solid foods like sandwiches, fruit, cookies, and cheese are allowed through security and in your carry-on bag. Liquids and gels like peanut butter, hummus, yogurt, jam, and honey follow the 3.4-ounce liquid rule. You can bring an empty water bottle through security and fill it at a water fountain or refill station after you pass the checkpoint.

Alcohol is not allowed in carry-on bags, even if it is sealed. You can purchase duty-free alcohol at the airport after security and bring it on the plane if it is in a sealed bag, but opening it during the flight is illegal. Alcohol in checked bags is allowed in most cases, though some airlines restrict it.

Baby food and breast milk are exempt from the 3.4-ounce liquid rule if you are traveling with an infant. Declare them to the TSA officer, and they will inspect them separately if needed.

Items banned from all flights

Weapons including firearms, explosives, flares, and realistic replicas are banned from both carry-on and checked bags. Lighters and lighter fluid are prohibited in carry-on and checked bags. Flammable liquids like paint thinner, gasoline, and certain cleaning products cannot fly.

Sporting equipment like baseball bats, pool cues, and ski poles are prohibited in carry-on but allowed in checked bags. Martial arts weapons including nunchucks, throwing stars, and brass knuckles are banned from both. Realistic toy guns and replica weapons may be confiscated even if they are not functional.

If you are unsure whether an item is allowed, check the TSA website's "What Can I Bring?" tool or contact your airline directly. It is better to know before you arrive at the airport than to discover a problem at security.

Frequently Asked Questions

Can I bring a lighter in my carry-on bag?

No. Lighters are banned from both carry-on and checked bags on all flights from U.S. airports. This includes disposable lighters, refillable lighters, and electronic lighters. If you smoke, plan to purchase cigarettes and a lighter at your destination.

Are hair straighteners and curling irons allowed?

Yes, hair styling tools with cords are allowed in carry-on bags. They must be cool before you pack them. Cordless tools that use butane cartridges are prohibited because butane is flammable. Check the label on your tool to see what fuel source it uses.

Can I bring my own snacks and sandwiches?

Yes. Solid foods including sandwiches, fruit, nuts, and baked goods pass through security without restriction. Spreads like peanut butter and jam are limited to 3.4 ounces. Bringing your own food saves money and lets you control what you eat during your flight.

What happens if I accidentally pack a banned item?

TSA officers will confiscate it. You will not be fined or arrested for an honest mistake, but you will lose the item. If you realize before you reach security that you have something banned, you can leave it with a friend, throw it away, or check your bag instead of carrying it on.

Do the rules change for international flights?

TSA rules are the same for all flights departing from U.S. airports, whether domestic or international. However, the country you are flying to may have different rules for what you can bring into that country. Check with your destination country's customs authority before you pack items like certain foods, plants, or medications.