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The 5 Best Extension Cords for Your Home and Garage of 2023

Jun 19, 2023

We’ve updated this guide and we remain confident in our picks. Our favorite is the Southwire 1638SW0061 Polar/Solar Supreme Extension Cord.

If you’ve always just bought whichever extension cord happens to be sitting on the shelf at your local hardware store, you’re missing out on cords that are safer, more durable, and more flexible than the ones most commonly available at brick-and-mortar retailers, and they’re much easier to use in cold weather. After spending more than 45 hours researching over 65 different extension cords, talking with two safety experts, and testing 12 of the most promising for flexibility—some even in zero-degree temps—we recommend the U.S. Wire & Cable 50 FT. Extreme All-Weather Extension Cord. For a more stylish indoor option, we like the Cordinate Décor Extension Cord with 3 Grounded Outlets.

With a solid power rating and durable construction, this cord can safely handle any job around a home or garage. Plus, it's the most flexible cord we’ve tested, even in freezing temps.

*At the time of publishing, the price was $75.

The U.S. Wire & Cable 50 FT. Extreme All-Weather Extension Cord offers an excellent combination of functionality and usability. The thick, 12-gauge wires inside are rated to handle up to 15 amps—as much as most residential breakers will allow—making it safe to use with most tools and equipment. It's also the most flexible cord we’ve ever used, so it's as easy to work with in the height of summer heat as it is the depths of a near-zero-degree winter. The outlet end has a small LED that lights up when the cord is live. If you’re going to own only one extension cord, the 50-foot version is versatile enough to maneuver across a two-car garage, run between two rooms indoors, or stretch deep into a yard or driveway. We’ve seen it priced anywhere between $50 and $90, which may induce some serious sticker shock, but it's a reasonable price for a high-quality extension cord that can survive even the harshest conditions and has a lifetime warranty.

The Southwire cord is nearly identical to our top pick, but it's just a little stiffer and typically costs a bit more.

*At the time of publishing, the price was $60.

If the U.S. Wire & Cable isn't available, we also like the Southwire 1638SW0061 Polar/Solar Supreme Extension Cord. It has all the same characteristics of our top pick but is a little stiffer, making it just a tad trickier to coil up at the end of the day.

Like the Southwire, the Clear Power cord is nearly identical to our pick but has a little locking switch at the plug end to secure the connection. It's an okay feature, but not an essential one.

*At the time of publishing, the price was $57.

Another very similar option is the Clear Power CP10091 50 ft TPE Rubber Heavy Duty Extension Cord, which proved easy to handle. It's a little stiffer than our main pick but otherwise offers the same powering capabilities, and it has a locking switch at the plug end that prevents whatever you’re plugging into it from disconnecting accidentally. It's a decent feature, but we have suspicions about the mechanism's long-term durability. Also, there are enough other ways to secure the plugged connection of an extension cord that we don't think this is necessary.

The Iron Forge cord doesn't cost as much as our other picks, but it's not as easy to coil. It can carry the same amount of power, though.

May be out of stock

*At the time of publishing, the price was $45.

If you live in a warmer climate and don't need a cord that's flexible through the cold depths of winter, we also like the Iron Forge Tools 12/3 SJTW Heavy Duty Yellow Outdoor Extension Cord. It has the same power rating as our other picks, but the cable sheath is made of a different material (the kind most hardware store cords are made of), so it's stiffer in general and won't be as loose in colder temperatures. In our testing it sat flat on the ground, but it's harder to spool than our other picks.

Unlike many of its competitors, the Cordinate indoor cord has a sleek look and a flat plug that won't get bent or pulled from an outlet. We love that it's available in a multitude of colors, especially neutrals.

If you need an indoor cord just to plug in a lamp or phone charger, the 10-foot Cordinate Décor Extension Cord with 3 Grounded Outlets is the best choice. Unlike many inexpensive cords for indoor use, the Cordinate has a third prong for grounding, which provides extra protection against electrical shorts and shocks. Plus, it has a flat plug that's less likely to be bumped out of the socket by furniture, pets, or people; half-plugged cords and damaged wiring can increase the risk of fire. Some other indoor cords share these characteristics, but what really sets the Cordinate apart is that it's available in a wide array of colors. Cords like these aren't meant to be used outdoors or with high-power tools and equipment—they’re intended only for low-power use around the home or office.

All of the picks in this guide are available primarily from online retailers; the best extension cords are rarely found on shelves at big-box hardware stores. But if you need a cord right now, we do have tips for how to pick the best extension cord at your local hardware store.

The best extension cords aren't typically sold in physical stores.

Quality extension cords cost more, but they can last you a lifetime.

Almost every one of our picks has an elastomer sheath for ultimate flexibility.

Don't be cavalier with your cords. Fires are a very real hazard.

For this guide, we spoke with John Drengenberg, consumer safety director at Underwriters Laboratories (UL), an independent consumer safety organization. Drengenberg has been with UL for more than 50 years, over which time he earned the nickname "Mr. Safety." We also consulted with Jeff Lutke, principal engineer of UL's Wire & Cable division.

Former Wirecutter senior editor Mark Smirniotis, the original author of this guide, covered electrical and charging products for three years as a staff writer at Wirecutter, writing about everything from rechargeable batteries to surge protectors to generators. During that time, he frequently consulted with electrical engineers and safety organizations like UL.

Senior staff writer Doug Mahoney spent 10 years in high-end home construction as a carpenter, foreman, and jobsite supervisor in the Boston area. He was also on the safety committee of the company he worked for, which included the maintenance of safe jobsites (including proper extension cord usage), and has been reviewing tools and gear since 2007. Between these two roles, Doug has used and evaluated extension cords for at least the past 20 years.

High-end outdoor extension cords are not cheap, but they’re durable, safe, and far easier to use than the generic orange cords you’ll find tangled in garages nationwide. Our picks are noticeably better, whether you’re plugging in an extra fan in the summer, inflating a tire, or powering a wireless speaker for a party. And if you’re planning on doing any home-improvement or maintenance projects, the cords we recommend are properly sized and rated for as much power as a home outlet can produce, making them compatible with larger tools such as portable table saws and air compressors.

In addition to heavy-duty and outdoor cords, we also considered indoor extension cords for all the other light-duty needs that come up in everyday life. Just like their beefier siblings, these cords may seem similar on the shelf, but small differences can make for a safer cord that looks better when you need it to charge a phone on your power-starved nightstand or plug in a lamp on that one table that's nowhere near a wall outlet.

A good extension cord should have a 15-amp power rating and 12-gauge wires, and be tested and approved by a third party—either UL or Intertek. It should have an elastomer sheath that makes it flexible enough to consistently lay flat on the ground and easy to coil up. We also prefer models with lighted ends, which make it easy to see whether power is running through the cord. Extension cords come in various lengths, but we think 50 feet is the most practical for all-around use because it's long enough to reach the lawn, but not so long that it's heavy and difficult to coil up.

Here's more information about the features we looked for in an extension cord—and why they’re important.

Third-party approved, SJEOW rated: Any cord marked by UL ("UL Listed") or Intertek ("ETL Listed") has been tested to certain safety and function standards by a reputable third party. This ensures that the cord is of reliable quality and can be used safely within its given power rating. The specifics of this testing are held in a seemingly random string of letters printed on the side of the cord. Through our research, we found that the best cords for home use are designated as SJEOW and SJEOOW.

Every letter in these codes has a meaning (PDF), and by understanding them, it's easier to know the differences between our preferred SJEOW and SJEOOW cords and the more commonly found, less-expensive SJTW cords, which populate the shelves of big-box stores. The most important of these letters, for our purposes, is the "E." This indicates that the sheath of the extension cord is made of an elastomer and not a thermoplastic, which is what the "T" in SJTW stands for. (Not to confuse matters further, but we should note that some elastomers are a form of thermoplastic.) The only difference between SJEOW cords and SJEOW cords is that the latter's outer sheath and inner-wire covers are both oil resistant; with the former, only the outer sheath is oil resistant.

Elastomer sheaths are preferable because they are very rubbery and flaccid. In our tests, they barely held any shape memory and consistently sat flat against the ground when unrolled, which greatly reduces any tripping hazard. Coiling them in at the end of the day is also much easier, as they fall naturally into even loops. Elastomer cords perform much better in extreme temperatures, too. For example, our top pick, an SJEOOW cord, has been approved for use in temperatures ranging from 221 degrees Fahrenheit to -94 degrees Fahrenheit, while the SJTW cords we looked at are typically approved to temperatures from 140 °F to -40 °F.

These temperature numbers on the SJTW cords may sound impressive, but Jeff Lutke, principal engineer of UL's Wire & Cable division, explained that these numbers only indicate that the cord can be wrapped around a test spool without cracking or breaking. It does not indicate the temperature at which the cord starts to become stiff. What these numbers do indicate, and what we saw in our testing, is that the elastomer coating on SJEOW and SJEOOW cords has a much higher resilience to temperatures than the thermoplastic-insulated SJTW cords. This difference is manifested in their general handling at any temperature.

A 50-foot, 12-gauge wire: How much power a cord can carry is related to the wire's thickness and the length of the cord. The longer the cord, the thicker the inside wires need to be to handle the same amount of power. For home use, a 50-foot extension cord with a 12-gauge wire thickness offers the best in portability and power.

A 12-gauge, 50-foot wire can handle 15 amps, which matches most residential breakers and many older fuses. These breakers prevent overloaded circuits by cutting the power if you try to draw more than 15 A. If you’re using a cord rated for only 10 A or 12 A, as many cheaper ones are, your breakers won't help you avoid an overload if you plug in something with a higher amp rating, with consequences from the unfortunate (a tripped breaker) to the catastrophic (fire). A cord capable of 15 A is more expensive than its light-duty cousins but will satisfy the demands of heavy-duty electric tools like circular saws long after you’ve forgotten its rating. But as a cord gets longer, its amp rating starts to drop. So a cord like our pick, which can handle 15 A at 50 feet, can still power 15 A at 100 feet, but only for short periods of time.

If you use cords that are too thin for the length and power you need, you can run into two problems. The most common is voltage dropping from the outlet to the far end of the cord. This can mess up different types of equipment in a few ways: Lights may dim, saws may not spin as fast, and some motors just won't work at all. That can cause safety issues of its own (slow saws won't cut cleanly, which can make them harder to control). The biggest problem with an undersized cord is that it can actually start a fire. Pulling too much power through a too-small cord will cause it to heat up, eventually melting the jacket and exposing the bare wiring underneath.

For indoor cords that won't be subjected to much more than phone chargers, lamps, or small speakers, a 15 A power rating isn't as important. Even if all three of those items were plugged in, it's unlikely they’d use more than 7 A. That's why other features, like flush-mounted plugs and grounding pins that reduce the risk of shocks or fire, are more important for indoor cords.

A lighted end: We like extension cords that include a small LED light at the plug end to let you know when the cord is powered. If your cord is plugged in around a corner or otherwise out of sight, it's nice to know at a glance when the power is on and when it isn't.

Some cords also include locking brackets or switches to keep a plugged-in tool's power cord firmly attached to the extension cord's outlet. It's a nice-to-have feature, but it often adds bulk to the plug end, making it incompatible with recessed outlets such as those found on electric snow blowers or lawn mowers. Also, extension cords can lead rough lives—they’re frequently stepped on or dropped—so we see these brackets and switches as just another thing that can break. (You’ll still be able to use the cord itself, though.) There are ways of tying two cords together at the connection point to create the same kind of stability, if not more, without these drawbacks. If you feel strongly about having a separate holding bracket, there are many third-party cord locks available.

For indoor cords, we recommend flatter plugs that sit flush to the outlet. That helps prevent the plug from getting pulled out—or worse, partially pulled out—when you move a chair or a pet bumps into it.

We considered more than 55 extension cords with UL or Intertek listings from top online retailers, and then narrowed the list based on the power ratings and added features. To decide on our final picks, we tried out six indoor/outdoor cords and three indoor cords, examining each one and using them in a variety of environments to see which cords would survive trouble-free for years to come. In 2021, we tested an additional six options.

All of the cords we tried were reasonably flexible at room temperatures, so we decided to test them in more challenging conditions. We enlisted the aid of San Diego Cold Storage, which has a million cubic feet of cold storage warehouses, with some getting as cold as 0 ºF. Facilities manager Frank Plant arranged for us to store some of the most promising cords in one of the coldest corners of the facility for two days—when we returned, our thermometer read just 7 ºF. We then tested how well each cord could be stretched out, which ones kept their coiled shapes too tightly, which ones were usable, and which ones were too stubborn to get back into a tidy coil once we were done.

Perhaps more importantly, we used the cords on a day-to-day basis. This allowed us to get a better sense of their flexibility, how flat they sat, and how easy they were to coil properly. We strung them across a yard, down a driveway, and through a workshop. We used the cords to power high-draw tools like a table saw, an air compressor, and a leaf blower, among many other items.

During testing, we kept an eye on the outlet design—small differences in an extension cord's outlet can set the best ones apart from the mediocre. The receptacle should grip plugs firmly enough to keep them safely plugged in but smoothly enough that you don't have to struggle to plug them in or pull them apart. The longer the strain relief—the little plastic turtleneck that runs up the cord—the better the wires can resist pulling out the back of the receptacle from repeated bending at tight angles.

With a solid power rating and durable construction, this cord can safely handle any job around a home or garage. Plus, it's the most flexible cord we’ve tested, even in freezing temps.

*At the time of publishing, the price was $75.

If you buy only one extension cord, we recommend the U.S. Wire & Cable 50 FT. Extreme All-Weather Extension Cord. It has thick, 12-gauge wires inside that can handle up to 15 A of electricity, and it was the most flexible and floppy cord of any we tried. We even froze it to nearly 0 ºF for two days, after which we stretched it out flat without a problem and coiled it without kinks. This flexibility makes it safer and easier to use than the others, a fact that becomes most apparent in colder temperatures. The U.S. Wire & Cable cord is also oil resistant, making it more durable in more environments (like garages), and the outlet end lights up when power is on. This is not a cheap cord—we’ve seen it priced anywhere between $55 and $90—but its durable construction and lifetime warranty makes it a tool that you can expect to have for the long haul.

Like all of the cords we tested, the U.S. Wire & Cable 50 FT. Extreme All-Weather Extension Cord is rated for 15 A, making it hardy enough to handle any tools or equipment powered by a standard household plug, including larger items like compressors and table saws. The 12-gauge wire inside is thick enough to deliver the proper voltage from end to end, and the coating on the entire length of the cord (a jacket made of a rubbery elastomer instead of a plasticky vinyl) is not only weather resistant but also oil resistant. All the cords we tested were rated by UL to withstand UV rays and a bit of rain (marked with a "W" for weather resistance), but since our pick is also oil resistant, it won't break down when regularly dragged across oil- or grease-covered floors in garages or workshops. That makes it more versatile and more reliable, no matter what projects pop up years down the line.

Stiff cords that loop and twirl across a yard or floor create tripping hazards that can be made exponentially more dangerous if, say, the cord is plugged into a running table saw.

Most extension cords are plenty flexible when heated up in the sun, but SJEOW and SJEOOW cords like the U.S. Wire & Cable have elastomer sheaths, which are much more flexible and cold resistant than the thermoplastic sheaths found in SJTW cords (the kind you see in most hardware stores). After two days coiled in a deep freeze at SD Cold Storage, we threw the end of the U.S. Wire & Cable cord, and it snaked out without any indication of what it had been through. When we repeated this on the more-common thermoplastic SJTW cords, the worst ones recoiled like a spring, and others kept some of their stiff curves as they reached across the floor. The U.S. Wire & Cable cord had a floppiness the others—even the additional SJEOW-listed cords we tested—didn't.

This looseness means a much safer cord. Stiff cords that loop and twirl across a yard or floor create tripping hazards that can be made exponentially more dangerous if, say, the cord is plugged into a running table saw. The benefits of a floppy cord are also evident when it's time to stow it away. Because it has so little shape memory, the U.S. Wire & Cable cord feeds handily into a nice, even loop, making it easier to unravel the next time you use it. Trying to unsnarl a stiff cord is more akin to untangling a curling rat's nest of cables.

We really came to appreciate the U.S. Wire & Cable cord when we used it throughout a series of New England winters. It was there, on the coldest days, when we really valued what the U.S. Wire & Cable cord provides. With multiple cords laid out and in use, strewn across the snowy ground, only the U.S. Wire & Cable cord actually sat completely flat. The others retained some of their coil shape and here and there would loop up a couple inches off the ground, creating a serious tripping hazard. At the end of each day, coiling the U.S Wire & Cable cord back up went quickly and easily, a contrast to the others which we had a much harder time with.

The U.S. Wire & Cable also has an outlet that makes a smooth, firm connection with the power cords you plug into it. Overly tight outlets can make it difficult to get a plug all the way in, resulting in a poor connection and a higher risk of shocks or shorts, especially when exposed to any moisture. That can make it too easy to accidentally pull out a plug while you’re using a tool.

Our pick is 50 feet long, which we think is the best for general use, but the same cord is also available in lengths of 25 feet and 100 feet, if those better suit your needs.

If there is a downside to the U.S. Wire & Cable extension cord, it's the cost: We’ve seen it priced anywhere between $55 and $90. It's a substantial investment either way, but when compared to high-quality SJEOW and SJEOOW cords, the price isn't unreasonable—all of them exist in a similar price range. The same can be said for SJTW cords, which can cost up to $80. Speaking as people who have spent decades fighting with and tripping over cheaper cords, we’re confident that the U.S. Wire & Cable is considerably better than what you can pick up in a box store, and durable enough to justify the heavy initial investment.

Long-term test notes: Former Wirecutter senior editor Mark Smirniotis has had the U.S. Wire & Cable 50 FT. Extreme All-Weather Extension Cord for over three years now, and it continues to be the first cord that he reaches for. Though he hasn't subjected it to freezing temps since his initial testing, he's otherwise put it through the paces as best a non-pro can: It powered a table saw through a weekend of fence construction, it was left out in the sun for a couple weeks after powering some string lights for a party, and it's been coiled and re-coiled many times for smaller tasks like powering shop vacs or work lights. It's still in great shape. Perhaps most telling: A general contractor working on Mark's house needed a cord, and Mark offered the U.S. Wire & Cable (on pain of death if it wasn't returned). The owner of the company and the head of the crew both agreed it had the nicest feel of any extension cord they’d encountered—and wanted to know the brand so they could put a couple on their shopping lists.

New Hampshire-based writer Doug Mahoney has been using the cord for over a year on his farm. As a long-time user of box store cords, he has been amazed at how floppy the U.S. Wire & Cable cord remained throughout the brutal New England winter.

The Southwire cord is nearly identical to our top pick, but it's just a little stiffer and typically costs a bit more.

*At the time of publishing, the price was $60.

Like the Southwire, the Clear Power cord is nearly identical to our pick but has a little locking switch at the plug end to secure the connection. It's an okay feature, but not an essential one.

*At the time of publishing, the price was $57.

If the U.S. Wire & Cable cord is unavailable, we had very good experiences with the SJEOW cords we tested: the Southwire 1638SW0061 Polar/Solar Supreme Extension Cord and the Clear Power CP10091 50 ft TPE Rubber Heavy Duty Extension Cord. Both cords have the elastomer sheath and resulting floppiness that made our top pick so nice. In our tests these two were a little stiffer than the U.S. Wire & Cable, but not by much.

The Clear Power cord distinguished itself slightly thanks to the locking switch on the outlet end. It works fine, but given how roughly extension cords can be treated, we’re wary of its long-term durability. The switch looks sturdy, but we’re not sure it can hold up to years of being tossed in the corner of a garage, run over by a vehicle, or repeatedly dragged across a driveway and bounced up a curb. If holding the plugged connection is a concern, we recommend learning how to do it with an overhand knot.

These are the two other SJEOW cords we tested, but, given our experiences, we would expect similar performance out of any cord with the same rating. Models we did not test include the Bad Ass 50 Foot 12/3 SJEOW Cold Weather Lighted Extension Cord, the Iron Forge Tools 50 FT 12/3 SJEOW Heavy Duty Lighted Outdoor Extension Cable, the Carol All-Weather Extension Cord and the UltraXtreme Hi-Flex All-Weather Extension Cord.

The Iron Forge cord doesn't cost as much as our other picks, but it's not as easy to coil. It can carry the same amount of power, though.

May be out of stock

*At the time of publishing, the price was $45.

If you’re looking for a cheaper investment and don't mind a stiffer cord, we like the Iron Forge Tools 12/3 SJTW Heavy Duty Yellow Outdoor Extension Cord. Unlike our other picks, this isn't an SJEOW or SJEOOW cord, so it lacks the super-flexible elastomer jacket. But compared with the rest of the SJTW cords we looked at, the Iron Forge was the loosest and sat the flattest against the ground once unspooled. As the temperature drops, it's less likely to hold this characteristic.

Unlike many of its competitors, the Cordinate indoor cord has a sleek look and a flat plug that won't get bent or pulled from an outlet. We love that it's available in a multitude of colors, especially neutrals.

Compared with other cheap, nameless cords you’ll find in the corners of the internet and at discount stores, the Cordinate Décor Extension Cord with 3 Grounded Outlets offers three distinct advantages: a flat plug, a grounding wire, and an internal safety cover on each outlet that is similar to the tamper-resistance feature used in modern outlets and considered far safer for homes with small children. Those three features make it a great cord among a sea of options that are only good enough, and it costs just a few dollars more despite the advantages. An aesthetically pleasing fabric wrap is a welcome bonus, as is the wide variety of colors that it comes in.

We always recommend a flat plug for indoor cords. Because it sits flush against wall outlets, a flat plug is less likely to get bumped completely or partially out of the socket, which can make the connection more prone to electrical shocks if someone tries to unplug it. Many of the cheap indoor cords we’ve seen stick out from the wall and can easily be knocked or pulled.

Plus, the added grounding pin and wire makes it less prone to electrical shocks and shorts than ungrounded, two-prong variations. Not every low-power device requires a grounded outlet, but it's nice to have that option on a go-to cord, and it's much safer than using a grounding adapter.

Besides the safer plug design, the Cordinate Décor Extension Cord also looks better than cheaper indoor cords. In addition to the plastic jacket that protects the wires, this cord also has an attractive fabric wrap. It's a small but welcome touch if you’re going to see the cord constantly peeking out from behind your nightstand, side table, or dresser. The similar GE Designer Cord Pro comes in a few different colors and has three outlets, but there's one notable difference between the two: The Cordinate outlets include spring-loaded, internal covers that the GE cord lacks. This safety feature makes it harder for an inquisitive child or a clumsy adult to stick something inside and shock themselves.

Adding to the benefits of the Cordinate is the wide variety of fabric tones you can choose from, including pink, mint green, and a dark heather gray. This may seem trivial, but it can either add to the discretion of an extension cord (which are usually black, brown, or white) or create a purposeful pop of color.

The downside to any indoor extension cord is that many of the common ways people want to use them are exactly the kind of things safety experts told us not to do with an extension cord: running one behind a (flammable) couch, through dusty (flammable) corners, and kinked around a hard turn. Even in low-power uses, it pays to use common sense and some extra caution.

John Drengenberg, the consumer safety director at UL, accepts these types of cords as a necessity when you need to plug in a lamp or a phone charger, but he told us that they are often pushed beyond their limits. Problems commonly arise when they’re the only option around and get drafted for other purposes—like powering a space heater during a cold snap, or plugging in a blow dryer in a separate room when getting ready for an event. Oftentimes you’ll get away with these indiscretions, but that's what everyone thinks right before a fire starts.

Drengenberg also told us that modern PVC coatings can last a very long time, but older cords, or ones that don't go through any sort of safety testing, can wear too quickly. Unlike some cheap indoor cords with only a single layer of protection around each individual conductor, our Cordinate pick has a PVC jacket, plus a fabric wrapping for added durability, kink resistance, and a nicer look.

As basic as an extension cord may seem (just plug it in, right?), there are some things to keep in mind to help ensure the longevity of the cord as well as your own safety. We’ve listed the most important points below, but we also recommend looking at the cord safety tips from the Electrical Safety Foundation International.

Extension cords are for temporary use. Drengenberg was adamant about explaining this rule of extension cords first: If you’re running them all over your house, inside or out, you’re greatly increasing all of the variables that contribute to fire. Though it's understandable to need a cord from time to time, or even for a few days, you shouldn't use an extension cord for any installation that's likely to be permanent. Safety recommendations (and, in some cases, building codes) say that for a permanent application, you should have a real outlet installed by a qualified electrician.

Don't run extension cords under rugs, furniture, or pretty much anything else. Putting a cord underneath, behind, or through something puts it at higher risk of physical damage and, more catastrophically, can cause heat to build up. As heat builds up, protective coatings melt, and you’re left with hot wires and sparks, potentially under something flammable.

Don't connect multiple extension cords. Ratings for extension cords are set for the length of the cord—they don't carry over when chained together. The extra connections can cause added resistance; the extra length can cause voltage sags, leading to poor equipment performance; and the extra current drawn being through the cords can lead to heat buildup. All that said, if you absolutely have to, make sure to follow our next rule.

Make secure connections. All of our picks have firm and secure plug ends, but in certain situations, it's a good idea to eliminate the tension on the connection. This can be done with either a third-party cord lock or by learning how to safely knot the ends of the cord. There are two knots to use, both of which are prominent on construction sites: the single overhand knot and the more-stable doubled-up overhand knot.

Don't connect surge protectors to extension cords. The added connection has a small chance of causing a problem, but you should avoid plugging a surge protector into an extension cord, and vice versa. Too many outlets on the end of a cord make overloading the cord much easier, leading to increased heat and risk of fire; long cords may have increased resistance and power draw if packed onto a surge protector. If you need a longer cord, say, behind a media center, look for a surge protector with a built-in cord of that length. If you own your own home, consider having an electrician add an outlet where you need it.

"Weather resistant" isn't the same thing as waterproof. A little water won't hurt an extension cord, and a durable cord that's been well cared for, with no cuts or wear in the jacket, will be safe if it gets wet temporarily. But even weather-rated extension cords like our top pick, the U.S. Wire & Cable, aren't meant to be submerged. Connections are rarely waterproof, so if you’re using them outdoors for a few days, consider getting weatherproof connection boxes to reduce the likelihood of water infiltration.

Store your extension cords without kinks or knots. If you’re wrapping your cords around your arm, you’re doing it wrong. Learn how to properly store your cords to avoid damaging them—and even better, to make sure they’ll quickly stretch out flat when you need them.

The Yellow Jacket 2884 12/3 Heavy-Duty 15-Amp SJTW Contractor Extension Cord with Lighted Ends, the Ridgid 50ft. 12/3 Contractor Grade Indoor/Outdoor Extension Cord, the Flexzilla Pro Extension Cord, the Utilitech Pro Contractor Cord and the Bergen Industries 50 ft. SJTW Yellow 12/3 Outdoor Extension Cord are all SJTW cords and stiffer than our picks.

The Husky 50 FT Cold Weather Indoor/Outdoor Extension Cord is available at Home Depot nationwide, making it a solid choice if you need a cord today, or if our top pick is out of stock. While it lacks a lighted end, it was one of the floppier SJTW cords we tested.

The Voltec Industries 50-ft 15-Amp 300-Volt 1-Outlet 12-Gauge Yellow Outdoor Extension Cord has a durable construction, but it was the least flexible of any cord we tried. At low temperatures, it recoiled like a spring when we tried to stretch it out, and it's noticeably harder to manipulate even at room temperature.

AmazonBasics 16/3 Vinyl Outdoor Extension Cords are much thinner than the U.S. Wire & Cable and carry less power less safely. Both the 50- and 100-foot versions use a 16-gauge wire, making the former safe up to only 13 A and the latter safe to just 10 A. (And if you’re searching on Amazon, you’ll likely see the Coleman Cable options, with the same 16-gauge wire and low ratings, listed nearby.)

Though we used to recommend a Husky Cold Weather cord as a runner-up, other Husky-brand cords available at Home Depot are less impressive. The Husky 25 FT Medium Duty Indoor/Outdoor Extension Cord offers the same power-handling capacity and safety levels as our picks but lacks the added flexibility of the elastomer jacket on our top pick, the U.S. Wire & Cable.

In addition to the yellow Utilitech Pro extension cords, you’ll find the cheaper red Utilitech cords at Lowe's. Like the Husky cords, these common house-brand cords aren't made with the flexible and durable jackets we like, they lack lights in the outlet ends, and they don't offer a significant savings.

For indoor cords, the three-plug, indoor extension cord we examined from GE (the 12-foot, brown 51954 version) has a nearly identical cable to the 6-foot Wall Hugger version we once recommended. But the standard plug sticks out from the wall, which makes it more likely to be pushed and bent and also puts more strain on the cord's neck. Neither of those cords are grounded, either.

Though GE makes the GE Designer Cord Pro with similar construction and features as our indoor pick, the Cordinate Décor, it lacks the internal outlet covers that help lower the risk of electric shock if anything is jammed into the outlets. It also doesn't come in as many colors.

John Drengenberg, consumer safety director, Underwriters Laboratories, interview, August 25, 2016

Wire Gauge Reference Table (AWG), Bulk Wire

National Electrical Code Allowable Ampacities of Insulated Conductors Rated 0-2000 Volts (PDF), USA Wire & Cable, Inc.

Gary Weidner, Choosing and Using Extension Cords (PDF),

Doug Mahoney

Doug Mahoney is a senior staff writer at Wirecutter covering home improvement. He spent 10 years in high-end construction as a carpenter, foreman, and supervisor. He lives in a very demanding 250-year-old farmhouse and spent four years gutting and rebuilding his previous home. He also raises sheep and has a dairy cow that he milks every morning.

by Mark Smirniotis

We’ve spent dozens of hours researching and testing the best extension cords, and along the way have picked up tips to keep cords at their best.

by Mark Smirniotis

If you need an extension cord right now and can't wait to order a better one online, here are our tips for selecting the best one at your local hardware store.

by Harry Sawyers

Between the tree, the lights, tools, and accessories, we’ve got your home-decoration needs covered this Christmas.

by Grant Clauser and Adrienne Maxwell

We’ve picked the best gear you need for a great outdoor movie night.

Third-party approved, SJEOW rated: A 50-foot, 12-gauge wire: A lighted end: Long-term test notes: Extension cords are for temporary use. Don't run extension cords under rugs, furniture, or pretty much anything else. Don't connect multiple extension cords. Make secure connections. Don't connect surge protectors to extension cords. "Weather resistant" isn't the same thing as waterproof. Store your extension cords without kinks or knots.