In New York City, the self-defense weapons that are legal for an ordinary resident come down to a short list: pepper spray that meets state requirements, a folding knife with a blade under four inches carried concealed, and personal safety alarms. Stun guns, tasers, brass knuckles, switchblades, and throwing stars are crimes to possess, and carrying a firearm without a city-issued license is a felony. The rules around even the legal items are specific enough that it’s worth knowing them before you buy anything.
Pepper Spray
Pepper spray is the most straightforward legal self-defense tool in New York City. State law carves out a specific exemption from the general weapons ban for “self-defense spray devices,” but the exemption comes with conditions.1New York State Senate. New York Penal Law PEN 265.20 – Exemptions
A legal spray is pocket-sized and releases a chemical or organic substance meant to cause temporary discomfort or disability. State Department of Health regulations limit the canister size, and compliant products typically hold around three-quarters of an ounce of active formula. Larger canisters or industrial formulations don’t qualify.
You must be at least 18 and have no prior felony or assault conviction in any state. Purchases can only be made from a licensed firearms dealer or a licensed pharmacist, and at the point of sale you sign a state certification form confirming eligibility.2New York Codes, Rules and Regulations. 9 CRR-NY 474.5 Form – Certification for the Purchase of a Self-Defense Spray Device
Every legal canister carries a specific warning label stating that use for anything other than self-defense is a criminal offense, that the contents are dangerous, and that possession by anyone under 18 or anyone with a disqualifying conviction is illegal.1New York State Senate. New York Penal Law PEN 265.20 – Exemptions If you buy online or out of state and the product arrives without that label, it isn’t compliant with New York law. That matters: the exemption attaches to compliant devices.
Knives Under Four Inches, Carried Concealed
You can carry a knife in New York City, but the city’s rules are tighter than state law. NYC Administrative Code § 10-133 makes it illegal to carry any knife with a blade of four inches or longer in any public place, street, or park. It is also illegal to wear or carry any knife in open view, regardless of blade length, unless you’re actively using it for a lawful purpose like work.
So a folding knife with a blade under four inches, concealed in your pocket, is legal. A pocket clip that leaves the handle visible above your waistline, a sheath on your belt, or a kitchen knife riding at the top of your bag can all be read as “open view.” The NYPD enforces this regularly.
New York State repealed its ban on gravity knives in 2019. The NYPD has cautioned that gravity knife possession can still lead to arrest depending on the circumstances, particularly where the knife appears to be possessed for an unlawful purpose.3NYPD. Knives – What You Need to Know Switchblades, ballistic knives, and metal knuckle knives remain illegal to possess under state law regardless of size.
Personal Safety Alarms
Personal safety alarms are completely legal. These keychain-sized devices emit a loud siren when activated. Because they aren’t weapons and don’t cause physical harm, they fall outside the weapon statutes entirely. No age requirement, no certification form, no licensed dealer. If you’re under 18, have a disqualifying conviction, or simply don’t want to navigate the pepper spray rules, this is the option available to you with no legal risk.
Stun Guns and Tasers Are Still Illegal Here
This is where a lot of people get the wrong answer from a quick search. Stun guns and tasers are prohibited weapons under New York Penal Law § 265.01(1), and that language is still on the books.4New York State Senate. New York Penal Law PEN 265.01 – Criminal Possession of a Weapon in the Fourth Degree
A 2019 federal ruling, Avitabile v. Beach, found the state’s blanket stun gun ban unconstitutional and got wide press coverage, which led many people to believe these devices were now legal. The legislature never amended the statute. In March 2025, a different federal judge in Calce v. City of New York upheld both the state and city bans. Possession in New York City remains a criminal offense, and buying or carrying a stun gun or taser here is a real legal risk.
Weapons You Cannot Possess at All
Penal Law § 265.01 makes it a crime to simply possess certain weapons, regardless of intent. No threat, no use, no leaving your home required. The prohibited list includes:4New York State Senate. New York Penal Law PEN 265.01 – Criminal Possession of a Weapon in the Fourth Degree
- Pistols, revolvers, short-barreled shotguns, short-barreled rifles, and assault weapons without a New York City premises or carry license
- Stun guns, tasers, and electronic dart guns
- Billies, blackjacks, bludgeons, and sandbags
- Metal knuckles, plastic knuckles, and metal knuckle knives
- Switchblades, cane swords, and ballistic knives
- Shuriken (throwing stars) and chuka sticks
Criminal possession of a weapon in the fourth degree is a Class A misdemeanor, punishable by up to one year in jail.5NYCourts.gov. Types of Criminal Cases Body armor is legal for most New Yorkers, but federal law bars anyone convicted of a violent felony from purchasing, owning, or possessing it.6Office of the Law Revision Counsel. 18 U.S. Code 931 – Prohibition on Purchase, Ownership, or Possession of Body Armor by Violent Felons
When You Can Actually Use What You Carry
Carrying a legal item and using it legally are two separate questions. Under Penal Law § 35.15, you may use physical force when you reasonably believe it is necessary to defend yourself or someone else from what you reasonably believe is the imminent use of physical force.7New York State Senate. New York Penal Law PEN 35.15 – Justification; Use of Physical Force in Defense of a Person
Two words carry the standard: “reasonably” and “imminent.” The threat has to be happening now or about to happen, not something that happened earlier or might happen eventually. Your belief has to be one a reasonable person in your situation would share. Spraying someone because of a vague feeling of unease on a subway car isn’t likely to qualify.
The pepper spray exemption itself only covers use “under circumstances which would justify the use of physical force” under Article 35.1New York State Senate. New York Penal Law PEN 265.20 – Exemptions Use it in a situation that doesn’t meet the standard, and the exemption doesn’t protect you.
Duty to Retreat
New York is one of about a dozen states that imposes a duty to retreat before you can use deadly physical force. If you know you can avoid the confrontation by retreating with complete safety, you must do so.7New York State Senate. New York Penal Law PEN 35.15 – Justification; Use of Physical Force in Defense of a Person
The exception is your own home. If someone is attacking you in your dwelling and you were not the initial aggressor, you have no duty to retreat before using deadly force. The duty also doesn’t apply when you reasonably believe the attacker is committing or attempting kidnapping, rape, forcible sexual abuse, or robbery.
Proportional Force
Force must be proportional to the threat. Pepper spray against someone grabbing at your bag is likely proportional. A knife against someone who shoved you in an argument is almost certainly not. Courts look at the totality of the circumstances, and overreacting can turn a self-defense claim into a criminal charge against you.
Places Your Legal Items Can’t Go
Even perfectly legal pepper spray or a legal pocket knife can create problems in the wrong building.
Federal Buildings
Federal law prohibits bringing any “dangerous weapon” into a building owned or leased by the federal government where federal employees work. The penalty is up to one year in prison for simple possession and up to five years if the weapon is intended for use in a crime.8Office of the Law Revision Counsel. 18 U.S. Code 930 – Possession of Firearms and Dangerous Weapons in Federal Facilities The Department of Homeland Security has confirmed that mace and stun guns count as dangerous weapons under this statute, and no federal security committee can waive the prohibition.9U.S. Department of Homeland Security. FAQ Regarding Items Prohibited from Federal Property The one statutory exception is a pocket knife with a blade under two and a half inches. Courthouses, post offices, Social Security offices, and the IRS office in lower Manhattan all count.
Airports
Pepper spray cannot go through airport security in a carry-on. TSA allows one container of up to four fluid ounces in checked baggage, as long as it has a safety mechanism to prevent accidental discharge, and the formula contains no more than two percent tear gas.10Transportation Security Administration. Pepper Spray Knives of any kind are banned from carry-on bags but allowed in checked luggage if properly sheathed.11Transportation Security Administration. Knives
The Everyday-Object Trap
Under Penal Law § 265.15, possessing any weapon or instrument designed or adapted for use primarily as a weapon creates a legal presumption that you intend to use it unlawfully against another person.12New York State Senate. New York Penal Law 265.15 – Presumptions of Possession, Unlawful Intent and Defacement
In practice, a heavy flashlight, a baseball bat, or a length of chain can be treated as an illegal weapon when the circumstances suggest you’re carrying it to hurt someone rather than for a legitimate reason. Prosecutors can point to verbal threats, aggressive behavior, the time and location, and the absence of any lawful purpose. An aluminum bat in a gym bag on the way to a batting cage is sports equipment. The same bat at 2 a.m. outside a bar after an argument is evidence of unlawful intent. NYPD officers have wide discretion in making that initial call.