Duplicate Keys — What You Need to Know

Most people don't think about duplicate keys until they need one urgently — standing outside their home after losing their only copy, or realizing they have no spare to give a housesitter or a family member who needs occasional access. At that point, the absence of a duplicate becomes an immediate problem.

Getting duplicate keys made is one of the simplest and most practical things you can do as a homeowner or renter. Here's what's worth knowing about how key duplication works, where to get it done, and a few things that affect the quality of the copy you end up with.

Why Duplicate Keys Are Worth Having

When you buy a new lock, it almost always comes with two keys for a reason. Having a spare isn't paranoia — it's practical planning for situations that happen regularly:

Lost keys — The most obvious scenario. If you lose your only key and have no spare, you're looking at a lockout or paying for a locksmith to rekey or cut a new key. A duplicate costs a fraction of either of those.

Giving access to others — A family member, a trusted neighbor, a dog walker, a housecleaner, a contractor doing work while you're away. These are routine situations that come up for most households and they're far easier to handle when you already have a spare key available.

Key failure — Keys wear down over time. A key that's been duplicated many times, or one that's been bent, corroded, or exposed to a lot of wear, can start to fail. Having an intact spare means that failure doesn't strand you.

Where to Get a Duplicate Key Made

The most practical option for most standard keys is a hardware store, big-box retailer, or local locksmith.

Hardware stores and big-box retailers — Home Depot, Lowe's, and similar stores have key cutting kiosks or counters that handle standard residential keys for a few dollars. The MinuteKey kiosks in many stores are self-service and work for common key types.

Local locksmith — A local locksmith can cut duplicate keys for a wider range of key types, including older or less common cuts that automated kiosks sometimes struggle with. For keys that have given you trouble at kiosks, a locksmith with a manual cutter is the more reliable option.

Mobile locksmith — If you need keys cut at your location — at home, at your car, or somewhere else — a mobile locksmith brings the cutting equipment to you. Useful when you need multiple copies made or when the key is for a vehicle that requires programming alongside cutting.

What Affects the Quality of a Duplicate Key

Not all duplicates are made equally, and the quality of the copy matters more than most people realize.

Always duplicate from the original key, not from a copy. This is the most important thing to know about key duplication. Every time a key is duplicated, the machine reads the cuts on the existing key and reproduces them — but small tolerances mean each copy is very slightly less precise than the one before it. A copy of a copy accumulates that imprecision. By the second or third generation copy, you may end up with a key that technically fits but is stiff in the lock, requires jiggling, or fails under certain conditions. Starting from the original every time avoids this entirely.

The quality of the blank matters. Key blanks vary in quality. The inexpensive blanks used in automated kiosks are generally fine for standard use, but for keys you're relying on heavily or cutting for security-sensitive locks, a locksmith using higher-quality blanks is worth the modest additional cost.

Worn keys produce worn copies. If the key you're duplicating is already showing wear — the cuts are rounded, the blade is bent, the shoulder is damaged — the duplicate will inherit those imperfections. If your original key is in rough shape, a locksmith can sometimes work from the lock itself rather than the worn key to produce a more accurate copy.

Key Duplication at Home — Is It Worth It?

The original question of whether you can duplicate keys at home has a short answer: technically yes, practically no.

Key duplication machines similar to what locksmiths use are available for purchase, but they represent a significant investment that only makes sense for someone cutting keys regularly. Mold-based methods using putty or wax can produce rough copies but lack the precision of machined cuts and aren't reliable for daily use.

For almost everyone, getting a duplicate cut at a hardware store or locksmith is the right answer — it's fast, inexpensive, and the quality is reliably better than any DIY alternative.