The TSA rules for carry-on items
The Transportation Security Administration (TSA) sets the rules for what goes in your carry-on bag on domestic U.S. flights. The basic rule is straightforward: you can bring almost anything that is not a weapon, explosive, or flammable. Most everyday items — clothes, books, electronics, toiletries under 3.4 ounces — pass through security without a second look.
The catch is that some items are restricted by amount or type. Liquids, gels, and aerosols follow the 3-1-1 rule: each container holds 3.4 ounces or less, all containers fit in one clear quart-sized plastic bag, and you bring one bag per person. This applies to shampoo, lotion, toothpaste, peanut butter, yogurt, and anything else that pours or spreads. Solid food — a sandwich, apple, or granola bar — has no limit.
International flights from the U.S. follow the same TSA rules. If you are flying into another country, that country's rules may differ on arrival, but TSA does not stop you at the gate. Check with your destination country's customs rules before you pack.
Key Takeaways
- Liquids, gels, and aerosols must be 3.4 ounces or smaller per container, and all containers must fit in one quart-sized clear plastic bag.
- Solid food, electronics, and most everyday items have no carry-on limit as long as they fit in your bag and pass through the X-ray machine.
- Knives, razors, lighters, and tools longer than 7 inches are prohibited in carry-on; checked baggage rules differ for some items.
- Batteries, power banks, and electronic devices are allowed in carry-on but not in checked bags in some cases.
- TSA PreCheck and Clear do not change what you can pack — they only speed up the security line.
Liquids, gels, and aerosols: the 3-1-1 rule explained
The 3-1-1 rule exists because TSA screens liquids differently than solids. A liquid can be harder to scan, so TSA limits the amount you can bring. The rule applies to anything that flows, spreads, or sprays: shampoo, conditioner, lotion, sunscreen, deodorant, toothpaste, peanut butter, jam, honey, yogurt, soup, and mascara all count.
Each container must be 3.4 ounces (100 milliliters) or smaller. A 3.5-ounce bottle will be confiscated. All containers go into one clear quart-sized plastic bag — the kind you can buy at any drugstore or grocery store for a few cents. You bring one bag per person. If you are traveling with a partner, you each get one bag.
Solid items do not follow the 3-1-1 rule. A full-size stick of deodorant is fine; a gel deodorant must be 3.4 ounces or less. A bar of soap, solid perfume, or lip balm has no limit. If you are unsure whether something counts as a liquid, ask yourself: would it spill if the container tipped over? If yes, it is a liquid.
Electronics and power banks
Laptops, tablets, phones, cameras, and headphones are allowed in carry-on bags. You will remove your laptop at security and place it in a bin for X-ray screening, just like your shoes and belt. Tablets and phones usually stay in your bag.
Power banks and portable chargers are allowed in carry-on but not in checked baggage. TSA limits you to two power banks per person, and each must have a capacity of 100 watt-hours or less. Most standard phone chargers fall well under this limit. If your power bank is larger or you are unsure of the watt-hour rating, check the label or the manufacturer's website before you pack.
Spare lithium batteries — the kind you might carry for a camera or electronic device — are prohibited in checked bags but allowed in carry-on. You can bring a maximum of two spare batteries per person, and they must be in your carry-on bag, not checked.
Tools, sharp objects, and items that look like weapons
Knives of any size are prohibited in carry-on, even small pocket knives or butter knives. Razors, box cutters, and utility knives are also banned. Scissors are allowed only if the blades are shorter than 4 inches and the edges are rounded. Nail clippers, tweezers, and safety razors are permitted.
Tools longer than 7 inches are not allowed in carry-on. This includes screwdrivers, wrenches, hammers, and pliers. Smaller tools — a multi-tool with blades under 7 inches, for example — may be allowed, but TSA officers have final say at the checkpoint. If you need tools at your destination, pack them in checked baggage instead.
Sports equipment and hobby gear have specific rules. Baseball bats, golf clubs, and ski poles are prohibited in carry-on but allowed in checked bags. A tennis racket or badminton racket is allowed in carry-on. Darts, throwing stars, and martial arts weapons are prohibited in both carry-on and checked bags.
Medications and medical devices
Prescription medications in their original labeled containers are allowed in carry-on and checked bags in any amount. You do not need a copy of your prescription, but having one can help if TSA has questions. Over-the-counter medications like ibuprofen, acetaminophen, and allergy pills are also allowed.
Liquid medications — insulin, cough syrup, or liquid vitamins — do not follow the 3-1-1 rule. You can bring more than 3.4 ounces if you declare it to TSA at security. Place the medication in a separate bag and tell the officer it is a liquid medication. They may open it and test it, but you will not lose it.
Medical devices like 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; inform TSA at the checkpoint.
Food and beverages
Solid food has no restrictions in carry-on bags. You can bring sandwiches, fruit, vegetables, cheese, crackers, granola bars, chocolate, and baked goods. Peanut butter, jam, honey, and other spreads must follow the 3-1-1 rule because they are considered liquids or gels.
Beverages are not allowed through security. You cannot bring a bottle of water, juice, coffee, or soda in your carry-on. You can buy a drink after you pass through security and bring it onto the plane. Most airports have water fountains and shops where you can fill a reusable bottle or purchase a drink.
Frozen food is allowed in carry-on if it is completely solid when you go through security. A frozen gel pack or ice pack is also allowed if it is completely frozen solid. If it has any liquid or slush, TSA will confiscate it.
What happens if you pack a prohibited item
If TSA finds a prohibited item in your carry-on bag, you have three choices: put it in checked baggage if you have time, leave it at the checkpoint, or throw it away. TSA does not charge you or fine you for bringing a prohibited item by mistake. They straightforward will not let it through security.
If you are unsure whether an item is allowed, ask a TSA officer before you pack or at the checkpoint. You can also check the TSA website or call the TSA helpline at 1-855-787-2227 before you travel. Response times vary, but TSA tries to answer questions within a few hours.
Frequently Asked Questions
Can I bring a lighter or matches in my carry-on?
No. Lighters and matches are prohibited in both carry-on and checked bags on commercial flights. This includes disposable lighters, refillable lighters, and all types of matches. The only exception is a single lighter in your checked bag if it has a safety cap and is placed in a protective case, but most airlines do not allow this either — check with your airline before you pack.
Are hair straighteners and curling irons allowed?
Yes, hair straighteners and curling irons are allowed in carry-on bags. They are treated as regular electronics. You can use them in your hotel room, but not on the plane. If your device has a lithium battery, it must be in your carry-on bag, not checked.
Can I bring a full-size bottle of perfume or cologne?
Only if it is 3.4 ounces or smaller. A standard 1.7-ounce bottle fits the rule. Larger bottles must go in checked baggage. Solid perfume or perfume oil is not subject to the 3-1-1 rule if it is truly solid.
What about vaping devices and e-cigarettes?
Vaping devices and e-cigarettes are allowed in carry-on bags only. They are prohibited in checked baggage because the battery poses a fire risk. You cannot use them on the plane. Vape liquid follows the 3-1-1 rule for liquids.
Do I need to remove my shoes and belt at security?
TSA PreCheck members do not need to remove shoes, belts, or light jackets. Standard security screening requires you to remove shoes, belts, and outerwear. This is not a carry-on rule — it is a screening procedure. Your shoes and belt go in a bin and go through the X-ray machine with your bag.