What the TSA allows in carry-on luggage

The TSA (Transportation Security Administration) permits most everyday items in your carry-on bag, but a specific list of items is banned entirely. You can bring clothing, shoes, books, electronics, toiletries in containers of 3.4 ounces or smaller, and most food items. You cannot bring sharp objects (knives, box cutters, razors), lighters, flammable items, or containers of liquid or gel larger than 3.4 ounces—even if the container itself is mostly empty.

The rules are the same whether you fly domestically or internationally from a US airport, though some countries have stricter rules for what you can bring into that country once you land. Your airline may also have its own size and weight limits for carry-on bags, which are often stricter than TSA rules.

The TSA website has a searchable tool called "What Can I Bring?" where you can type any item and see the current rule. Rules do change, and the tool reflects the most recent guidance. If you are unsure about something specific, that tool is faster and more reliable than calling ahead.

Key Takeaways

  • Liquids and gels in containers larger than 3.4 ounces are banned from carry-on bags, even if the container is mostly empty.
  • Sharp objects, lighters, and flammable items cannot go in your carry-on under any circumstances.
  • Your airline sets its own size and weight limits for carry-on bags, which may be stricter than TSA rules.
  • The TSA's "What Can I Bring?" tool on their website lets you search any item to confirm the current rule before you pack.
  • Rules for what you can bring into your destination country are separate from TSA rules and vary by country.

The 3.4-ounce liquid rule and what counts as a liquid

The TSA defines liquids and gels broadly: this includes not just water and juice, but also shampoo, conditioner, lotion, toothpaste, peanut butter, yogurt, honey, and aerosols like deodorant or hairspray. A container larger than 3.4 ounces (100 milliliters) cannot go in your carry-on, even if it is half empty. A full-size tube of toothpaste is typically 5.5 ounces and is not permitted.

All liquids and gels must fit inside a single clear plastic bag, roughly the size of a quart-sized freezer bag. You are allowed one bag per person. The TSA checks this bag at security, so it should be straightforward to remove and open. Solid items—like a bar of soap, a stick of deodorant, or a solid perfume—are not subject to the liquid rule and can go anywhere in your carry-on.

If you want to bring full-size bottles of shampoo, lotion, or other liquids, pack them in your checked bag instead. There is no liquid limit for checked luggage.

Electronics and batteries in carry-on bags

Laptops, phones, tablets, cameras, and headphones are all allowed in carry-on bags. You will need to remove your laptop and large electronics from your bag at security screening. Batteries are permitted in carry-on bags under specific rules: standard AA, AAA, C, D, 9-volt, and button-cell batteries are fine. Lithium batteries (the kind in phones and laptops) are allowed only if they are installed in the device itself.

Spare lithium batteries—loose or in a separate charger—are not permitted in carry-on or checked bags on passenger flights. This is a safety rule, not a TSA preference. If you need to travel with a spare battery, contact your airline before you book to see if they have an exception or alternative.

Power banks and portable chargers are allowed in carry-on bags. Larger items like hair dryers and electric shavers are permitted as long as they do not contain flammable fuel (some older shavers did).

Food and beverages you can bring through security

Solid food items—sandwiches, fruit, cookies, nuts, cheese, chocolate—can go through security and into your carry-on. Liquids and gels do not: peanut butter, yogurt, jam, honey, and hummus are all banned from carry-on bags because they are classified as gels. You can buy beverages (water, juice, coffee) after you pass through security, but you cannot bring them through the checkpoint.

If you are traveling internationally, some countries restrict what food you can bring into them. The rules vary widely and depend on the country and the type of food. Check the customs rules for your destination before you pack.

Items that are sometimes confusing or commonly questioned

Scissors with blades shorter than 4 inches are allowed in carry-on bags. Scissors longer than 4 inches or with a sharp point are not. Nail clippers and nail files are permitted. Razors and box cutters are banned entirely.

Matches and lighters are not allowed in carry-on or checked bags. This includes disposable lighters and refillable lighters. Some airlines permit one book of safety matches in checked baggage, but not in carry-on.

Tools like screwdrivers, wrenches, and pliers are banned from carry-on but allowed in checked bags. Sporting equipment varies: golf clubs, baseball bats, and ski poles are allowed in checked bags but not carry-on. Bicycles can be checked if they are disassembled and packed in a bike bag or box.

Medications in their original labeled containers are allowed in carry-on bags. Bring a copy of your prescription or a doctor's letter if the medication is a controlled substance or an injectable. Syringes are allowed if they are accompanied by medication.

How airline carry-on limits differ from TSA rules

The TSA does not set a size or weight limit for carry-on bags—they only screen what goes through security. Your airline sets those limits, and they vary. Most airlines allow one carry-on bag (roughly 22 × 14 × 9 inches) and one personal item (a purse, backpack, or laptop bag). Some airlines charge a fee for a second carry-on or have stricter dimensions.

Budget airlines like Spirit and Frontier have smaller carry-on allowances and charge for anything beyond a personal item. Legacy carriers like Delta, United, and American typically allow a standard carry-on and a personal item at no extra charge. Check your airline's website before you pack to confirm their specific limits.

If your bag is oversized, the airline may gate-check it (take it at the boarding gate and put it in the cargo hold) at no charge, or they may charge a fee. Arriving early gives you a better chance of fitting your bag in the overhead bin before it fills up.

What to do if you are unsure about a specific item

Use the TSA's "What Can I Bring?" search tool on their website before you pack. Type the item name and you will see whether it is allowed in carry-on, checked baggage, or both. The tool is updated regularly and reflects current rules.

If you are traveling internationally, check the customs and import rules for your destination country. The US State Department website has links to customs information for most countries. Rules about food, plants, alcohol, and other items vary widely.

If you are still unsure after checking both sources, contact your airline directly. They can tell you their specific policy and whether they have any exceptions. Calling or emailing before you pack is faster than discovering a problem at the airport.

Frequently Asked Questions

Can I bring a full-size bottle of shampoo or lotion in my carry-on?

No. Any liquid or gel larger than 3.4 ounces is banned from carry-on bags. Full-size bottles of shampoo, lotion, and similar products are typically 5 to 16 ounces and must go in your checked bag. You can buy travel-size bottles (3.4 ounces or smaller) or pack full-size bottles in checked luggage.

Are medications allowed in carry-on bags?

Yes. Medications in their original labeled containers are allowed in carry-on bags. If you are bringing a controlled substance or injectable medication, bring a copy of your prescription or a letter from your doctor. Syringes are allowed if they are with the medication they are meant for.

Can I bring a lighter or matches on the plane?

No. Lighters and matches are banned from both carry-on and checked bags on passenger flights. This is a safety rule enforced by the TSA and the FAA.

What if my carry-on bag is too big for the overhead bin?

The airline may gate-check it (take it at the boarding gate and load it in cargo) at no charge, or they may charge a fee depending on their policy. Arriving early gives you the best chance of fitting your bag in the bin before it fills up. Check your airline's website for their specific oversized bag policy.

Can I bring food through security?

Solid food items like sandwiches, fruit, and nuts can go through security. Liquids and gels like peanut butter, yogurt, and jam cannot. You can buy beverages after you pass through security, but you cannot bring them through the checkpoint.