The TSA sets the rules, but the airline has the final say

The Transportation Security Administration (TSA) publishes a list of items you can bring through security in your carry-on bag, but the TSA does not pack your bag—your airline does. What TSA permits, your airline may restrict further. What one airline allows, another may not. The safest approach is to check your specific airline's carry-on policy before you pack, because the airline staff at the gate make the final decision about what boards the plane.

The TSA's basic rule is straightforward: items that could be used as weapons or to damage the aircraft stay in checked luggage or stay home. Liquids, gels, and aerosols follow a separate rule. Everything else—clothes, electronics, books, toiletries in solid form—generally moves through security without a second look.

Key Takeaways

  • The TSA permits most solid items in carry-on bags, but your airline may have stricter rules about size, weight, or specific categories.
  • Liquids, gels, and aerosols are limited to 3.4 ounces per container and must fit in a single quart-sized clear plastic bag.
  • Sharp objects, tools longer than 7 inches, and anything that looks like a weapon must go in checked luggage.
  • Check your airline's website for carry-on dimensions and weight limits before you pack, because gate agents can refuse oversized bags.
  • Electronics larger than a laptop (like a full-size tripod or power drill) may be permitted but should be declared to TSA officers before screening.

Liquids, gels, and aerosols: the 3-1-1 rule

The TSA's 3-1-1 rule is the most common source of confusion at security. Each container of liquid, gel, or aerosol can hold no more than 3.4 ounces (100 milliliters). All containers must fit inside a single quart-sized clear plastic bag—roughly 7 inches by 8 inches. You are allowed one bag per person. Anything larger than 3.4 ounces goes in checked luggage.

This rule covers shampoo, conditioner, lotion, sunscreen, toothpaste, deodorant, mascara, liquid eyeliner, foundation, and any spray or foam product. Solid deodorant, solid perfume, and bar soap are not liquids and do not count toward the limit. Frozen items are treated as liquids if they are still partially frozen when you reach security; fully frozen solid items may be permitted, but TSA officers have discretion, so expect to be asked.

Pack the bag with liquids at the top of your carry-on so you can remove it quickly at the security checkpoint. TSA officers will ask you to take it out before your bag goes through the X-ray machine.

Items that must stay in checked luggage

Sharp objects longer than 7 inches must be checked. This includes kitchen knives, box cutters, and most scissors. Pocket knives and multi-tools with blades are also prohibited in carry-on bags. Razors with exposed blades stay in checked luggage; cartridge razors (the replaceable-blade kind) are permitted in carry-on.

Tools longer than 7 inches—hammers, wrenches, saws, drills, crowbars—go in checked luggage. Smaller tools like a 6-inch adjustable wrench or a screwdriver may be permitted in carry-on, but check with your airline first. Sporting equipment with sharp edges or points, like ski poles, ice axes, or fishing rods, must be checked.

Firearms, ammunition, and realistic-looking replica guns are prohibited in carry-on bags entirely. Firearms must be unloaded, declared to the airline at check-in, and packed in a locked hard-sided container in checked luggage. Ammunition must also be in checked luggage in a manufacturer's container or an equivalent hard-sided container.

Flammable items—lighters, matches, lighter fluid, paint thinner, aerosol cans of spray paint—are prohibited in both carry-on and checked luggage on passenger aircraft. The only exception is one lighter or one pack of safety matches in your carry-on bag, and only if you keep it on your person (not in your bag). Many airlines prohibit even this exception, so check before you pack.

Electronics and power banks

Laptops, tablets, phones, cameras, and headphones are permitted in carry-on bags. You will be asked to remove laptops and large electronics from your bag at security so they can be X-rayed separately. Smaller electronics like phones and earbuds can stay in your bag.

Power banks (portable chargers) are permitted in carry-on bags only, not in checked luggage. The TSA limits power banks to 100 watt-hours (Wh) or 27,000 milliamp-hours (mAh). Most standard phone chargers fall well under this limit. Check the label on your power bank for the watt-hour rating; if it is not listed, the mAh number divided by 270 gives you a rough watt-hour equivalent. Power banks larger than 160 Wh are prohibited entirely.

Drones, e-cigarettes, and vaping devices are permitted in carry-on bags. Spare lithium batteries for cameras or other devices must be in carry-on bags, not checked luggage, because lithium batteries pose a fire risk in the cargo hold. You are limited to two spare batteries per device, and they should be in their original packaging or have tape over the terminals to prevent short circuits.

Sports equipment and musical instruments

Most sports equipment can be checked or carried on, depending on size and what your airline allows. Bicycles, skis, snowboards, golf clubs, and fishing rods must be checked because they exceed carry-on size limits. Tennis rackets, baseball bats, and hockey sticks may fit in the overhead bin if they are under your airline's length limit—typically 22 inches for carry-on items. Check your airline's policy before you pack.

Musical instruments are treated differently than other sports equipment. The TSA permits full-sized guitars, violins, cellos, and similar instruments in carry-on bags if they fit in the overhead bin or under the seat in front of you. Some airlines require you to purchase an extra seat for a full-sized instrument or to check it. Call your airline before your flight to confirm their policy. Smaller instruments like ukuleles and mandolins almost always fit in carry-on bags without issue.

Everyday items that are often questioned

Nail clippers, tweezers, and small scissors (under 7 inches) are permitted in carry-on bags. Nail files are also allowed. Razors with cartridge blades (the replaceable kind you use daily) are permitted; straight razors and razors with exposed blades must be checked.

Medications in their original labeled containers are permitted in carry-on bags in any quantity. Bring a copy of your prescription or a doctor's letter if you are carrying large quantities or if the medication looks unusual. Syringes are permitted if they are accompanied by injectable medication; pack them in a clear plastic bag and declare them to TSA officers.

Food is permitted in carry-on bags if it is solid. Peanut butter, jam, honey, and other spreads are gels and must follow the 3-1-1 rule. Solid foods like sandwiches, fruit, cookies, and cheese are not restricted. Some international flights have restrictions on fresh produce, meat, and dairy, so check your destination's rules if you are traveling outside the United States.

Oversized carry-on bags and airline restrictions

The TSA does not enforce carry-on size limits—your airline does. The standard carry-on size is 22 inches long by 14 inches wide by 9 inches tall, but airlines vary. Some allow bags up to 24 by 16 by 10 inches; others are stricter. Check your airline's website for exact dimensions before you pack. A bag that fits on one airline may be too large for another.

Gate agents can refuse to let oversized bags board, even if you packed them according to TSA rules. If your bag is borderline, pack light enough that you can move items to checked luggage if asked. Many airlines charge a fee for checked bags, so knowing your airline's carry-on policy saves you money and stress at the gate.

Frequently Asked Questions

Can I bring a full-size bottle of shampoo if I check it?

Yes. The 3-1-1 rule applies only to carry-on bags. Checked luggage has no limit on liquid volume, though most airlines limit checked bag weight to 50 pounds total. Pack liquids in the center of your bag surrounded by clothes to reduce the risk of leaks.

Are lighters really not allowed?

Most airlines prohibit lighters entirely in both carry-on and checked bags. The TSA permits one lighter or one pack of safety matches in your carry-on bag only if you keep it on your person, but many airlines override this rule. Check your airline's policy before you pack.

What happens if I accidentally bring a prohibited item to security?

TSA officers will confiscate it. You can ask to speak with a supervisor, but the decision is final. You cannot go back through security to check the item or move it to checked luggage. Leave prohibited items at home or pack them in checked luggage.

Can I bring my laptop in my carry-on bag?

Yes. You will need to remove it at security so it can be X-rayed separately, but it stays in your carry-on bag during the flight. The same applies to tablets and other large electronics.

Do I need to declare my power bank at security?

No declaration is required if it is under 100 Wh. However, if you have questions about whether your power bank meets the limit, show it to a TSA officer before you go through the checkpoint.