What the TSA allows in your carry-on bag
The TSA (Transportation Security Administration) allows most everyday items in your carry-on: clothing, books, electronics, toiletries in containers 3.4 ounces or smaller, and solid foods like sandwiches or fruit. You cannot bring liquids, gels, or aerosols larger than 3.4 ounces—this includes shampoo, toothpaste, peanut butter, yogurt, and sunscreen. Sharp objects like knives, scissors with blades longer than 4 inches, and tools are prohibited. Firearms, ammunition, and realistic replica weapons are never allowed.
The rules are the same whether you fly domestic or international within the United States. If you are connecting to another country, that country's rules may differ, so check with your destination airline before you pack. Some items—like lighters or e-cigarettes—have specific limits: one lighter is allowed, but it must be in your carry-on, never in checked baggage.
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, so checking before your trip is worth the two minutes.
Key Takeaways
- Liquids, gels, and aerosols must be 3.4 ounces or smaller and fit in a single quart-sized clear bag; this includes toothpaste, shampoo, lotion, and peanut butter.
- Sharp objects like kitchen knives, box cutters, and scissors with blades over 4 inches are prohibited in carry-on bags.
- Electronics like laptops, phones, and tablets are allowed and do not count toward liquid limits, but you must remove them at security.
- Solid foods like bread, fruit, cheese, and cooked meat are permitted; anything spreadable or in a container counts as a liquid or gel.
- Some items like lighters and e-cigarettes have special rules—one lighter is allowed in carry-on only, never checked baggage.
The 3-1-1 liquid rule explained
The TSA's 3-1-1 rule is the most important thing to remember: 3.4 ounces (100 milliliters) per container, 1 quart-sized clear plastic bag, 1 bag per person. All your liquids, gels, and aerosols must fit inside that single bag and go through security screening separately.
Measure by the container size, not how full it is. A 4-ounce bottle of shampoo is prohibited even if it is half empty. Travel-size bottles work because they are labeled 3.4 ounces or less. You can buy empty bottles at drugstores and fill them from larger bottles at home, or purchase travel-size versions of your regular products.
Common items that count as liquids or gels: toothpaste, deodorant (gel or cream), sunscreen, lotion, shampoo, conditioner, face wash, mascara, liquid eyeliner, foundation, concealer, lip gloss, honey, peanut butter, jam, yogurt, pudding, and creamy salad dressing. Solid deodorant, solid perfume, and lipstick in stick form are allowed in unlimited quantities.
Electronics and chargers in your carry-on
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 the security checkpoint and place them in a separate bin for X-ray screening. Phones and small devices can stay in your bag.
Chargers and charging cables have no restrictions. Power banks (portable battery chargers) are allowed, but they must be in your carry-on, never in checked baggage, because of fire risk. The TSA does not limit how many you bring.
Headphones, smartwatches, and wireless earbuds are fine. If you are bringing a drone, check with your airline first—some allow them in carry-on, others do not, and rules vary by airline.
Food and beverages you can bring through security
Solid foods pass through security with no restrictions: sandwiches, fruit, vegetables, cheese, crackers, cookies, chocolate, nuts, and cooked meat are all allowed. You can bring a full meal if you want. Frozen foods are permitted if they are completely solid when you go through security; if they have any liquid or gel, they follow the 3.4-ounce rule.
Beverages are not allowed through security—you cannot bring a bottle of juice, coffee, or water past the checkpoint. You can buy drinks after security at airport shops, or bring an empty water bottle and fill it at a water fountain or refill station once you are past the checkpoint. Many airports now have free water refill stations near gates.
Peanut butter, honey, jam, and other spreads are gels and must follow the 3.4-ounce rule. Yogurt and pudding are also gels. Solid chocolate, peanuts, and dried fruit have no limit.
Items you cannot bring in carry-on
Sharp objects are the biggest category of prohibited items. Kitchen knives, box cutters, razors, and scissors with blades longer than 4 inches cannot go in your carry-on. Scissors with blades 4 inches or shorter are allowed. Tools like hammers, screwdrivers, wrenches, and saws are prohibited.
Weapons and weapon-like items are never allowed: firearms, ammunition, explosives, flares, pepper spray, and realistic replica guns. Even if you have a permit to carry a gun at home, you cannot bring it on a plane in carry-on. Firearms must be unloaded, declared to the airline, and packed in checked baggage in a locked hard-sided container.
Lighters and matches have special rules. You can bring one lighter in your carry-on only (not checked baggage). Matches are prohibited entirely. E-cigarettes and vaping devices are allowed in carry-on but prohibited in checked baggage.
How to pack efficiently within the rules
Start by laying out everything you think you need, then sort items into categories: clothing, toiletries, electronics, and food. For toiletries, measure each container and set aside anything over 3.4 ounces. Transfer what you need into travel-size bottles or buy travel versions. Place all liquids, gels, and aerosols into your quart-sized clear bag before you leave home—do not wait until you are at the airport.
Pack heavier items like shoes and books at the bottom of your bag, then layer clothing on top. Electronics and chargers go in a separate pocket or pouch so you can remove them quickly at security. Keep your clear liquid bag on top or in an straightforward-to-reach spot.
Wear slip-on shoes to speed up security screening. Put your ID and boarding pass in your front pocket. If you are bringing a laptop, position it so it comes out first when you open your bag.
What happens if you accidentally pack a prohibited item
If TSA finds a prohibited item in your carry-on at the checkpoint, you have a few options: you can go back to the ticket counter and check the item in checked baggage (if it is allowed there), you can leave it behind, or you can go back to your car or a friend outside security. You will not be fined for an honest mistake, but you may miss your flight if you have to go back.
If you are unsure whether something is allowed, ask a TSA officer at the checkpoint before you go through the scanner. They can tell you on the spot. The TSA website's "What Can I Bring?" tool is also fast and accurate.
International flights departing from the United States follow the same TSA rules for carry-on. However, if you are connecting through another country or flying into another country, that country's rules may be stricter. Check your destination country's aviation authority website or call your airline to confirm.
Frequently Asked Questions
Can I bring a full-size bottle of shampoo if I check my bag?
Yes. Checked baggage has no liquid restrictions. You can pack full-size bottles, jars, and containers of any size in your checked bag. However, if your bag is lost, those items are gone, so many travelers pack travel sizes in carry-on and leave full sizes at home.
Are medications allowed in carry-on?
Yes. Prescription and over-the-counter medications in pill, tablet, or capsule form are allowed in unlimited quantities. Liquid medications like cough syrup or insulin are allowed in carry-on in reasonable quantities beyond the 3.4-ounce limit—you do not need to fit them in your quart bag. Keep medications in their original labeled containers and bring a copy of your prescription or a doctor's note if you are concerned.
Can I bring a lighter or matches?
You can bring one lighter in your carry-on only. It must be a standard lighter (not a torch lighter). Matches are not allowed in carry-on or checked baggage. Lighters are prohibited in checked baggage because of fire risk.
What if my carry-on bag is too big?
Airlines set their own size limits for carry-on bags, typically around 22 by 14 by 9 inches. If your bag is too large, the gate agent will ask you to check it. You will not be charged if it is your first bag, but you will lose access to your items until you land. Measure your bag before you travel or use a sizer at the airport ticket counter.
Can I bring a power bank or portable charger?
Yes, power banks are allowed in carry-on only, not checked baggage. You can bring multiple power banks. They must be in your carry-on because lithium batteries pose a fire risk in the cargo hold.