Don't Beep! — a fun guide to airport security

Briefing

What it's all for

Security screening isn't an exam or an interrogation. It's a quick check, after which everyone on board knows nothing dangerous is flying with them.

Flight safety

Nothing that could harm people or the aircraft should make it into the cabin: weapons, explosive and flammable substances, sharp objects.

The same for everyone

Every passenger goes through screening — first-time flyers and frequent flyers alike. Flight crews and airport workers are screened too.

It's not suspicion

If you're asked to open your bag or get a pat-down, that's routine. Some checks are random, others happen because something on the X-ray screen is unclear.

In the US, passenger screening is run by the Transportation Security Administration (TSA). You can decline it, but then you won't get past the checkpoint.

At home

Pack so the detector stays silent

Half of security happens at home, over an open suitcase. Five minutes of packing will save you twenty minutes of nerves.

ID on top
Keep your REAL ID or passport and your boarding pass where you can grab them with one hand. Save your mobile boarding pass to your phone's wallet — airport Wi-Fi can be moody. Kids under 18 don't need ID on domestic flights.
Liquids in a bag
Put containers of up to 3.4 oz (100 ml) in one clear, quart-size zip-top bag. Pack it at the top of your backpack: in a standard lane, you'll be asked to take it out.
Electronics within reach
Your laptop and tablet should come out in five seconds, not after an excavation under your sweaters.
Batteries stay with you
Power banks and spare lithium batteries travel in your carry-on. FAA rules don't allow them in checked baggage.
Sharp things go in checked baggage
Knives, box cutters, scissors with blades over 4 inches and tools over 7 inches belong in the suitcase you check.
Clothes without extra metal
A belt without a chunky buckle and as few bracelets and chains as possible. Good news: in most lanes, your shoes can now stay on.
Medicines: declare them
Liquid medications over 3.4 oz are allowed in reasonable quantities — just tell the officer at the start of screening. Labeled containers make any questions easier.
Leave plenty of time
Airlines usually recommend arriving 2 hours before a domestic flight and 3 hours before an international one. Check current wait times in the MyTSA app.

At the airport

7 steps from curb to gate

The whole route on a single belt. Seven stops — and you're at the gate.

Check-in and bag drop

What to doCheck in online or at a kiosk, and drop off your checked bags before security — once you're through the checkpoint, getting back to the counters is a hassle.

Common mistakeChecking a suitcase with a power bank inside. Spare batteries aren't allowed there, so your bag may be opened and inspected.
ID check

What to doAt the podium, hand a TSA officer your REAL ID-compliant license or passport. At many airports a scanner reads your ID and pulls up your flight, so you may not even need your boarding pass. Have TSA PreCheck? Look for its dedicated lane.

Common mistakeShowing up with a license that isn't REAL ID-compliant. Since February 2026, that means a $45 TSA ConfirmID fee and extra checks — and no guarantee you'll get through.
Getting ready at the belt

What to doGrab a bin. Take off your jacket and belt, and empty your pockets: phone, keys, change, wallet. In a standard lane, laptops and other electronics bigger than a phone go in a separate bin, and so does your liquids bag. Shoes can usually stay on.

Common mistakeSlipping your phone into your jacket pocket “just for a second.” The jacket rides off into the X-ray, and you're left hunting for your phone in every bin.
Metal detector or body scanner

What to doWalk through when the officer waves you on. In the body scanner, stand on the footprints, raise your arms and hold still for a couple of seconds.

If it beepsNo big deal. You may be asked to remove any metal you forgot and try again, or an officer will give you a quick pat-down.

Common mistakeBeeping back. The detector is just doing its job — smile and check your pockets.
X-ray machine

What to doWhile you walk through, your belongings ride through the X-ray machine. The operator watches the screen: organic materials show up orange, metal blue, and anything mixed green.

Common mistakeReaching into the tunnel for your bag while the belt is still moving. Wait — it'll come to you.
Additional screening

What to doIf something on the screen is unclear, an officer will search your bag in front of you. You may get a pat-down, or your hands and bag may be swabbed for traces of explosives. It's standard procedure.

Common mistakeReaching into your bag while it's being searched, or arguing. Answer questions calmly — it's faster that way.
Repacking

What to doTake all your bins and move to the repacking area — there are benches there. Check: ID, phone, laptop, belt, jacket. Stack the empty bins where staff can collect them.

Common mistakeLeaving your laptop in the bin. Count them: as many bins as you sent in, as many you take back.
Done!

Now you can breathe out, buy some water and go find your gate.

Reference

Can I take this?

Find an item and see where it goes — in your carry-on or in checked baggage.

How the operator sees your suitcase

What you can take in your carry-on and in checked baggage
Item	Category	Carry-on	Checked baggage	Comment
Water, juice, drinks	Liquids	Restricted	Allowed	Up to 3.4 oz in your carry-on. Bring an empty bottle and fill it up after security.
Shampoo, gel, cream, toothpaste	Liquids	Restricted	Allowed	Containers of up to 3.4 oz in your quart-size bag.
Perfume	Liquids	Restricted	Allowed	A bottle over 3.4 oz won't get through, even if it's almost empty: it's the container size that counts.
Aerosols: deodorant, hairspray, mousse	Liquids	Restricted	Allowed	Carry-on — up to 3.4 oz in your liquids bag. Checked — toiletry aerosols in limited quantities.
Duty-free alcohol	Liquids	Restricted	Allowed	Over 3.4 oz only if bought abroad and kept sealed in a tamper-evident bag with the receipt. Anything over 140 proof can't fly at all.
Peanut butter, jam, honey, yogurt	Food	Restricted	Allowed	For TSA, these count as liquids: up to 3.4 oz in your carry-on.
Sandwiches, fruit, cookies	Food	Allowed	Allowed	Solid food is fine. Flying into the US from abroad? Declare food to customs (CBP) on arrival.
Baby food, formula and breast milk	Food	Allowed	Allowed	Allowed in reasonable quantities over 3.4 oz. Tell the officer — they may be screened separately.
Pills and tablets	Medicines	Allowed	Allowed	No quantity limit, as long as they're screened. Labeled bottles make questions easier.
Liquid medicines over 3.4 oz	Medicines	Restricted	Allowed	Allowed in reasonable quantities — declare them to the officer at the start of screening.
Syringes, insulin	Medicines	Restricted	Allowed	Unused syringes are allowed together with injectable medication. Declare them at screening.
Phone, laptop, tablet	Electronics	Allowed	Better not	In checked baggage, electronics can get broken or lost — keep them with you in the cabin.
Power bank, spare batteries	Electronics	Restricted	Not allowed	Up to 100 Wh — fine; 101–160 Wh — with airline approval, two spares max; over 160 Wh — not allowed.
E-cigarette, vape	Electronics	Allowed	Not allowed	Carry-on only. No vaping on board.
Scissors	Sharp items	Restricted	Allowed	Blades shorter than 4 inches from the pivot point are allowed. The officer has the final say.
Knives, including folding ones	Sharp items	Not allowed	Allowed	Only plastic or round-bladed butter knives can go in the cabin. Even a tiny pocket knife goes in checked baggage.
Multi-tool	Sharp items	Restricted	Allowed	Allowed in your carry-on only if it has no blade — and most have one.
Disposable razor, electric shaver	Sharp items	Allowed	Allowed	Loose blades and straight razors go in checked baggage only.
Screwdrivers, wrenches, pliers	Tools & sports	Restricted	Allowed	7 inches or shorter — OK in your carry-on. Longer tools, hammers and crowbars go in checked baggage.
Bat, golf club, trekking poles	Tools & sports	Not allowed	Allowed	Check them in; larger items go as sports equipment.
Umbrella	Tools & sports	Allowed	Allowed	Allowed in carry-on and checked bags — rain or shine.
Thermos	Tools & sports	Allowed	Allowed	Empty — fine. With coffee inside, it's a liquid.
Lighter	Dangerous	Restricted	Restricted	One disposable or refillable lighter in your carry-on; torch lighters are banned. Checked — only empty or in a DOT-approved case.
Firecrackers, sparklers	Dangerous	Not allowed	Not allowed	Fireworks don't fly. Not even on the Fourth of July.
Pepper spray, mace	Dangerous	Not allowed	Restricted	Never in the cabin. One container of up to 4 fl oz with a safety lock is allowed in checked baggage.
Gasoline, lighter fluid, flammable paint	Dangerous	Not allowed	Not allowed	Flammable liquids are prohibited.

The TSA officer at the checkpoint makes the final call on whether an item goes through.

The rule

3-1-1

Three numbers worth remembering once and for all.

3.4 ozmaximum per container (100 ml)
1 quartone clear, quart-size zip-top bag — about 7 × 8 inches
1 bagper passenger

If you can pour it, spread it, squeeze it or spray it — security treats it as a liquid.

Trayce's golden rule

What counts as a liquid

drinks and soups
syrups
creams, gels and lotions
pastes, including toothpaste
oils
perfumes and sprays
mascara and liquid lipstick
peanut butter, jam, honey, yogurt
salsa, dips and spreads
snow globes

The catch

What counts is the size of the container, not how much is left in it. A 6 oz tube with the last drop of lotion won't get through.

Exceptions

Medications — in reasonable quantities. Declare them at the start of screening.
Formula, breast milk and baby food — in reasonable quantities, even if the baby isn't flying with you.
Medically necessary liquids — for example, juice or gel for diabetes.
Duty-free liquids — bought abroad, sealed in a tamper-evident bag with the receipt. Don't open it until your final destination, or it may be confiscated at your connection.

Good to know: at checkpoints with new CT scanners — and in TSA PreCheck lanes — your liquids and laptop can usually stay in your bag. The 3.4 oz limit still applies everywhere, so pack for 3-1-1 by default.

Not traveling light

Special cases

If you're not traveling light — with a child, a pet or a medical device — here's what you need to know.

With children

Little ones walk through the metal detector on their own or in your arms, and kids 12 and under can keep their shoes and light jackets on. Fold the stroller and put it on the belt — if it doesn't fit, an officer will inspect it by hand. Formula, breast milk and baby food are allowed in reasonable quantities. Kids under 18 don't need ID on domestic flights.

Tip: tell your child in advance that the bin will just give their toy a ride on the belt and bring it right back.

Wheelchair users and passengers with reduced mobility

Call TSA Cares at (855) 787-2227 at least 72 hours before your flight to arrange help at the checkpoint, and ask your airline for wheelchair assistance — TSA doesn't provide it. You won't have to get out of your wheelchair: an officer will screen you with a pat-down. Canes and crutches go through the X-ray or are checked by hand.

Pacemakers, implants, prostheses

Tell the officer before you reach the metal detector — a TSA disability notification card or your device ID card helps. You can ask for a pat-down instead. Joint replacements and metal plates often set off the detector — that's normal, just give a heads-up.

Medicines, syringes, insulin pumps

Declare medications, syringes and medical devices at the start of screening — you won't have to remove devices attached to your body. Many insulin pump and glucose monitor makers advise against sending them through body scanners or X-ray machines — in that case, ask for a pat-down and a hand inspection.

Flying abroad? Check whether your medicines are allowed into the destination country.

Religious clothing and head coverings

If your head covering needs a closer look, you can ask for a pat-down by an officer of your gender in a private screening area — or pat it down yourself and have your hands swabbed.

With a pet

Your pet comes out of the carrier and is carried through the metal detector in your arms — keep it on a harness or leash. The carrier goes through the X-ray machine. Keep your pet's documents handy.

Connecting flights

Arriving from abroad and connecting in the US? You'll clear customs (CBP), recheck your bags and go through TSA screening again. Water bought before the first check won't make it through, and duty-free liquids must stay sealed in a tamper-evident bag with the receipt.

Etiquette

Politeness works both ways

You have the right to

Watch while your belongings are searched.
Ask why you're being given additional screening and what the problem with an item is.
Opt out of the body scanner and get a pat-down instead.
Ask for a pat-down by an officer of your gender — in a private area, with a companion if you like.
Ask for fragile items and medical devices to be handled with care.
Ask for a supervisor on the spot, or file a complaint with TSA afterward.

Better not

Joke about bombs or weapons. Jokes like that are taken seriously: you can miss your flight, be fined or even be arrested.
Forget a gun in your carry-on. TSA finds thousands at checkpoints every year. Expect a hefty fine, possible arrest and losing your PreCheck.
Carry other people's belongings. Even if they ask very nicely.
Leave bags unattended. They may be taken away for inspection.
Argue with the officer. TSA makes the call — it's more productive to ask about your options.
Reach into the X-ray tunnel. Your things will come out on their own.

Hall of shame

Top 6 ways to set off a beep

Six mistakes that make the detector beep most often. Hover over a card to hear what they sound like.

#1

The runaway bottle

What happened: You forgot a bottle of water in your backpack.
How to avoid it: Finish it before security, or bring an empty bottle and fill it up afterwards.

#2

The exiled power bank

What happened: The power bank stayed in your checked suitcase.
How to avoid it: All batteries go in your backpack. Otherwise your checked bag may be opened and inspected.

#3

The undercover scissors

What happened: Scissors or a multi-tool were hiding in your toiletry bag.
How to avoid it: The day before, check your toiletry bag and every pocket of your backpack.

#4

The jingling human

What happened: Keys, coins and a belt with a buckle.
How to avoid it: All metal goes into your backpack while you're still in line.

#5

The giant lotion

What happened: A 6 oz tube with almost nothing left in it.
How to avoid it: Decant into travel bottles of up to 3.4 oz.

#6

The forgotten laptop

What happened: The laptop stayed behind in the bin.
How to avoid it: As many bins as you sent in, as many you take back.

Questions

Questions people are too shy to ask

Do I need to take off my shoes?

Usually not. Since July 2025, TSA no longer requires most travelers to remove their shoes. You may still be asked to if you need additional screening.

Do I need to take out my laptop?

In a standard lane, yes — anything bigger than a phone goes in its own bin. In TSA PreCheck lanes and at checkpoints with CT scanners, it can usually stay in your bag. Follow the officers' instructions.

Are body scanners harmful?

TSA's body scanners use millimeter waves, not X-rays, and the energy they emit is very low. If you'd rather skip the scanner, you can opt out and get a pat-down instead.

Will the X-ray machine damage my electronics or film?

Phones, laptops and digital cameras are fine. Undeveloped film is another story: CT scanners can damage it, so ask for a hand inspection — especially for film rated ISO 800 and up.

What happens if the metal detector beeps?

Nothing terrible. You may be asked to remove any metal you forgot and walk through again, or an officer will give you a quick pat-down.

What happens to a confiscated item?

You usually have options: go back and check it, hand it to someone who isn't flying, mail it to yourself if the airport offers a mail-back service, or voluntarily give it up.

Why was I sent for additional screening?

Some checks are random, others happen because something on the X-ray screen is unclear. If your boarding pass says SSSS, you've been selected for enhanced screening. It doesn't mean you're suspected of anything.

Can I bring water I bought after security?

Yes, you can buy any drinks past the checkpoint. But if you have an international connection with another security check, the bottle may not get through.

How long does screening take?

The screening itself takes a few minutes. Most of the time is spent in line, so check current wait times in the MyTSA app and allow extra time at peak hours.

Can I take a snow globe?

TSA treats it as a liquid. A snow globe about the size of a tennis ball or smaller (under 3.4 oz of liquid) can go in your quart-size bag. Anything bigger goes in checked baggage.

Clear security without a beep

What it's all for

Flight safety

The same for everyone

It's not suspicion

Pack so the detector stays silent

ID on top

Liquids in a bag

Electronics within reach

Batteries stay with you

Sharp things go in checked baggage

Clothes without extra metal

Medicines: declare them

Leave plenty of time

7 steps from curb to gate

Check-in and bag drop

ID check

Getting ready at the belt

Metal detector or body scanner

X-ray machine

Additional screening

Repacking

Done!