If you are trying to work out what to wear to DEF CON, here is the honest answer: dress for two climates, plan for a lot of walking, and pack more t-shirts than you think you need. Las Vegas in summer is brutally hot outside, while the conference halls are air-conditioned hard enough that people sit through talks in hoodies.
This guide covers a practical DEF CON outfit, a packing list, what changes for smaller BSides events, and a short note on your devices. We make hacker apparel, so we will point out where our shirts and hoodies fit, and where they do not. For this year's dates and venue details, check the official DEF CON site.
The short version:
- Wear a dark, comfortable t-shirt with an understated graphic, broken-in sneakers and one warm layer for the air conditioning.
- Stick to mostly black or charcoal with one accent color. It fits in, hides dust and sweat, and still looks intentional.
- Buy the boring gear first: a power bank, a multi-port USB-C charger, a refillable water bottle and a small sling bag.
- Skip costumes, tactical gear and brand-new shoes. The coolest look at a hacker con is the one that says you have been before.
What to Wear to DEF CON: The Short Answer
Nobody at a hacker conference expects a suit. The unofficial dress code is casual and practical:
- A t-shirt you like, ideally one that says something about you. Lighter colors are easier in direct sun.
- Shorts or light pants with pockets you will actually use.
- Broken-in walking shoes. Not new ones.
- One warm layer, a hoodie or sweatshirt, for the cold rooms.
- A small bag for water, a battery pack and that layer.
How to Look Good at DEF CON Without a Hacker Costume
Black is the unofficial uniform at DEF CON, and for good reason: it works with everything, survives a long day, and nobody looks twice. The trick to looking good rather than generic is restraint.
- Keep the palette mostly dark. Black, charcoal and grey for most of the outfit, plus one accent color such as red, acid green, electric blue or purple.
- Let one piece do the talking. A shirt with a graphic people in the room actually get beats a shirt that shouts "HACKER" in movie font.
- Add a light layer. An overshirt, a light jacket or a hoodie makes the outfit look finished and saves you in the cold halls.
- Wear clean, comfortable sneakers in black or grey that you have already walked in.
- Carry a small crossbody or sling bag instead of a giant backpack. A cap, sunglasses and a simple watch finish it.
Three DEF CON Outfits That Work
1. The classic con look
A black tee with an inside joke, dark jeans or cargos, black sneakers and a sling bag. Try the OSINT T-Shirt ("I don't stalk. I investigate.") or the Hashcat T-Shirt, both of which start conversations in line without trying too hard.
2. Dark with a neon accent
Black tee, a dark overshirt or light technical jacket, charcoal cargos and black sneakers, with one bright accent doing the work. The Red Team T-Shirt brings neon red and cyan, and the Wireshark T-Shirt brings the psychedelic eyes.
3. "I actually work in security"
The understated option, and often the coolest: a dark tee, relaxed black jeans, clean sneakers and a light bomber or overshirt. The Security Professional T-Shirt (HACKER crossed out, SECURITY PROFESSIONAL underneath) says this outfit out loud, while the Ethical Hacker T-Shirt keeps it to one word. For the quietest version, the Coffee & Hack T-Shirt has just a small chest print.
What Not to Wear to DEF CON
- Full tactical vests, fake military kit and pouches on everything.
- Brand-new shoes. Day two will punish you.
- Anything expensive or flashy that makes you look like an easy target. DEF CON rewards low-key.
- Costume-level hacker clichés. Plenty of people dress up for the parties, but in the halls, comfortable and understated fits in best.
Dress for Two Climates: Desert Outside, Cold Halls Inside
DEF CON happens every summer in Las Vegas, where afternoon temperatures often climb past 100°F. Walking between venues, or waiting outside for a ride, is hot, dry and bright.
Then you step inside. Casino and conference spaces run the air conditioning hard, and after an hour in a talk, plenty of people are cold. That swing is why layering beats any single "perfect" outfit.
Daytime: the t-shirt is the uniform
A breathable cotton tee is the default for good reason. Our hacker t-shirts are 180 GSM combed cotton in a regular unisex fit (Melange Grey is an 83/17 cotton and polyester blend), which is a normal, everyday weight.
Light colors like White and Melange Grey are a sensible pick if you will spend real time outdoors. Save the black shirts for inside.
Indoors and after dark: one warm layer
To be straight with you: a 320 GSM fleece-lined hoodie is warm. It is the right thing for a freezing talk track, the flight home and a late night, and the wrong thing for a midday walk on the Strip.
Carry it in your bag, put it on when the AC wins, and take it off at the door.
Shoes, Lines and Your Feet
Attendees joke about "LineCon" for a reason. You will stand in lines for badges, talks, villages and food, and walk long distances between them. Your shoes matter more than anything you wear above the ankle.
- Wear sneakers you have already broken in.
- Pack a second pair so each pair gets a day to dry out.
- Bring more socks than days. You will thank yourself on day three.
Hacker T-Shirts Are Part of the Culture
At most events a shirt is just a shirt. At a hacker conference, it is a conversation opener. People read each other's shirts in line, recognize a tool or an inside joke, and start talking.
A good hacker conference outfit works like a name tag you did not have to fill in. Our designs that tend to get a reaction, with each joke explained:
- OSINT T-Shirt: big red outlined letters with "I don't stalk. I investigate." in typewriter type underneath. OSINT means open-source intelligence, finding information from public sources, and the joke is how close that can look to stalking.
- Wireshark T-Shirt: stacked WIRESHARK lettering behind a pair of big, painted, psychedelic eyes. Wireshark is a free tool for capturing and reading network traffic, so the eyes are watching every packet.
- Hashcat T-Shirt: a black cat peeking over a blue-striped panel that reads "Cracking Jokes?" (crossed out) and "Cracking Hashes." Hashcat is a popular password-cracking tool, and the cat is a pun on the name.
- I Am Root T-Shirt: "I'M ROOT" in white block letters above a line drawing of a spaceship cockpit facing the stars. Root is the all-powerful admin account on Linux and Unix, so it means "I have full control." Yes, it also sounds like a certain talking tree.
- Phishing T-Shirt: yellow PHISHING, a boxed SCAM, and a credit card caught on a fishing hook. Phishing is the fake email or text that tricks people into handing over passwords or card details.
- No Logs, No Crime T-Shirt: one of our best sellers. The logic: if nothing was logged, there is no evidence anything happened. Every incident responder has felt this one.
For the full story behind each design, see what our hacker shirts mean.
Identity Shirts for Networking
DEF CON and BSides are also where people meet future coworkers, hiring managers and collaborators. A shirt that says what you do saves the first awkward minute.
Identity designs like Security Professional and Ethical Hacker are our best sellers, because security people like wearing their role:
- Security Professional T-Shirt: HACKER in red, struck through with a white line, with SECURITY PROFESSIONAL underneath. It is the word you use with friends versus the title on your LinkedIn profile. Black.
- Ethical Hacker T-Shirt: the quiet one. Just HACKER in spaced red capitals across the chest. In this crowd, "hacker" means someone who takes systems apart to understand them, ideally with permission.
- Red Team T-Shirt: RED TEAM in outlined red letters with a cyan offset that looks like a screen glitch. Red teamers are hired to attack an organization the way a real adversary would, so the defenders can learn.
- SOC Team T-Shirt: a cartoon monkey in sunglasses and a bow tie above the words SOC TEAM. The SOC (security operations center) is the team watching alerts around the clock. It comes in Melange Grey or White, which helps in the sun.
Not sure which role fits? Our guide to hacker shirts by security role breaks it down.
One Hoodie for the AC
You need exactly one warm layer, and it should be one you are happy to wear on repeat. Our hoodies are 320 GSM, brushed fleece on the inside, bio-washed and pre-shrunk.
- Security Professional Hoodie: our most-ordered piece, with the same crossed-out HACKER over SECURITY PROFESSIONAL. Black.
- Red Team Hoodie: the glitchy RED TEAM lettering on Black, White or Melange Grey.
Prefer no hood? Our crewneck sweatshirts are the same 320 GSM weight, so they are just as warm, not a lighter alternative. Every hooded option is in the hoodies collection.
What to Wear to BSides
BSides events are smaller, local and community-run, and they happen year-round in many cities. Dress for your local weather, not Las Vegas, and expect a relaxed crowd.
Jeans or shorts, a tee you like, and a layer in case the venue runs cold is plenty. TCM Security put it well in their Ethical Hacker Gift Guide, describing HackCloth as clothing "you can wear to the coffee shop or your local B-Sides." That is the bar we aim for: everyday clothes with a joke for the people who get it.
Because BSides crowds are small, an identity shirt works even better there. You will probably talk to half the room by lunch.
What to Buy for DEF CON: The Gear That Matters
If you are shopping before your first DEF CON, spend on comfort and power, not gadgets.
- Comfortable walking shoes. The most important purchase on this list.
- A 20,000 mAh power bank. Your phone runs all day. A bank this size is about 74 Wh, under the 100 Wh airline limit, and it must go in your carry-on, not checked luggage.
- A multi-port USB-C charger and spare cables. Hotel rooms never have enough outlets.
- A refillable water bottle. Las Vegas air is extremely dry.
- A small sling or backpack you can carry for 12 hours.
- Earbuds or headphones for noisy halls and any workshop with audio.
- Sunglasses and sunscreen for the walk between venues.
- A laptop and a USB-C hub, but only if you plan to do CTFs, villages or trainings. Check each event's requirements before buying anything.
What not to buy: a bag full of hacking gadgets you have never used. Villages and trainings often provide the hardware, so wait until you know what you will actually need.
Flying In From India or Abroad?
- Bring a US plug adapter. US outlets are Type A and B at 120 V. Most phone and laptop chargers handle both voltages, but check the label.
- Pack for the flight too. Long-haul cabins are cold, which is one more reason to bring the hoodie.
- Order clothes early. HackCloth ships free within India and free to the United States, so you can sort your con wardrobe before you leave or have it waiting in the US.
DEF CON Packing List
A simple DEF CON packing list that covers heat, cold and long days:
- One t-shirt per day, plus one or two spares for sweaty afternoons
- One hoodie or sweatshirt for the halls and the flight
- Shorts or light pants, plus something slightly nicer if you plan to hit an evening party
- Two pairs of broken-in, comfortable shoes
- More socks than days
- A refillable water bottle (the desert air is very dry)
- A battery pack and your own charging cable
- Sunscreen, sunglasses and a hat for the walks between venues
- Lip balm and hand sanitizer ("con crud," the bug many people catch after a big event, is real)
- A small backpack or sling bag
- A notebook and pen for talk notes and new names
- Empty space in your bag for shirts from the vendor area and villages
Lots of attendees fly home with new shirts from vendors, villages and official con merch, so pack a little light.
Con veterans also repeat some version of the 6-2-1 rule (some say 3-2-1): a minimum number of hours of sleep, two meals and one shower a day. The shirt-per-day math above assumes you honor the shower part.
A Quick Word on Your Devices
The DEF CON network is widely treated as hostile, for obvious reasons. A few habits worth packing:
- Turn off Wi-Fi and Bluetooth auto-join before you arrive.
- Charge from your own battery pack instead of unknown USB ports.
- Update your phone and laptop before you leave home.
- Bring only the devices you need, and log out of anything you do not.
No shirt will protect your phone. That part is on you.
Ordering Before a Con
Every piece ships from India, and standard shipping to the United States is free. Give yourself time before you fly: order well ahead of the con, not the week before.
For fit, check the size guide on the product page; size up for a relaxed fit. Returns are covered in our refund policy. Buying for someone else? Try our gift guide for ethical hackers and security pros.
FAQ
What should I buy for DEF CON?
Buy comfortable walking shoes, a 20,000 mAh power bank for your carry-on, a multi-port USB-C charger with spare cables, a refillable water bottle, a small sling bag, earbuds, and sunglasses with sunscreen. Only buy a laptop or hacking hardware if a specific CTF, village or training you plan to join requires it.
How do I dress to fit in and look good at DEF CON?
Wear mostly black or charcoal with one accent color, a t-shirt with an understated graphic or inside joke, dark jeans or cargos, clean broken-in sneakers and a light layer such as an overshirt or hoodie. Avoid tactical gear, costumes and anything flashy.
What color should I wear to DEF CON?
Black is the unofficial DEF CON uniform, and dark colors hide a long day well. Lighter tees such as white or grey are more comfortable if you will spend real time outdoors in the Las Vegas sun.
When is DEF CON?
DEF CON takes place every August in Las Vegas. DEF CON 34 ran from August 6 to 9, 2026 at the Las Vegas Convention Center; check the official DEF CON site for the next edition's dates.
What should I wear to DEF CON?
Wear comfortable, casual clothes: a breathable t-shirt for each day, shorts or light pants, broken-in walking shoes, and one warm layer such as a hoodie for the air-conditioned halls. Nobody expects business attire at DEF CON.
Is it cold inside DEF CON?
Often, yes. The halls are air-conditioned against the Las Vegas summer heat, and many attendees get chilly after hours in talks and lines. Bring a hoodie or sweatshirt you can keep in your bag.
Do people dress up at hacker conferences?
Mostly no. The norm is jeans or shorts with a t-shirt, often one featuring a hacker joke, a security tool or a past con. Evening parties can get more creative, but casual is standard.
Should I bring a hoodie to Las Vegas in August?
Yes, for indoors, flights and late nights, not for walking outside in the afternoon heat. A heavyweight hoodie like HackCloth's 320 GSM fleece-lined hoodies is warm, so carry it and put it on when the air conditioning gets to you.
What should I wear to BSides?
BSides events are small, local, community-run conferences, so dress for your local weather and expect a relaxed crowd. Jeans or shorts, a t-shirt you like and a light layer for the venue are plenty.