USB Extension Cables
Most devices that use USB cables come with one, but these prepackaged cables tend to be too short. Few things are as annoying as having to leave your device in a weird spot to recharge or trying to keep your phone charger from falling off the table. Using USB extension cords to get a little extra distance can be convenient or outright necessary in these situations.
There are a few facts to keep in mind when it comes to USB extension cables. First off, make sure you are picking out the correct type of extension cable. The average USB extension cord is going to be USB 2.0 A Male to Female. Some other types do exist, but typically “USB extension” means an A Male to Female cable.
Another other key detail to check is whether you need a USB 2.0 or 3.0 extension. Usually, the plastic inside the metal end of the USB cable will be color-coded, with 2.0 cables being black or white and 3.0 cables being blue. Not every manufacturer does this, so it never hurts to double-check your cable beforehand. You can use 2.0 extensions with other 3.0 cables, but you will only get USB 2.0 data and recharging speeds. If you want 3.0 speeds, every piece of equipment you are using must be 3.0 rated.
A 2.0 USB extension (left) vs. a 3.0 extension (right)
There are three different versions of USB extensions: passive, active, and extenders.
Passive USB Extensions
A passive USB cable is your standard, off-the-shelf cable. These cables are built using regular copper wiring with no extra bells or whistles. This makes passive cables low cost and easy to produce, but gives them a distance limit of 15 feet. If you are going beyond 15 feet, an active cable or extender must be used instead.
Passive cables cannot be chained together to get past the 15-foot limit. You can combine passive cables with active cables or extenders to go past 15 feet, but trying to get over the distance limit using only passive cables will not work. When chaining together any number of USB cables, you cannot have more than 15 feet of passive cable total throughout the entire chain.
Active USB Extensions
Active USB cables use internal electronics to boost signal strength, bypassing the 15-foot limit of passive cables. Because of the additional electronics, active cables can use more power than a passive cable. These extra components make active USB cables a little more expensive than their passive counterparts, even when the cables are the same length.
Out of all three USB extension options, active USB cables are the “medium-length” version. Typically, an active USB cord is used when you need to go more than 15 feet but less than 100 feet. While it is possible to chain multiple active cables together, each time the signal passes from one cable to the next it gets a little weaker. This signal degradation will lower overall signal quality and can even cause the signal to fade out completely as it tries to go from Point A to Point B.
USB extenders, also known as USB over Ethernet Baluns, are used for extremely long USB extensions. These devices are made in pairs, with one unit using a male USB and the other using female USB. Then an ethernet cable is run in-between both units, allowing an ethernet cable to be used as a USB extension cord. Distance limits can vary, but USB extenders typically have a maximum distance of 150 to 200 feet. They are also inexpensive, even when taking the ethernet cable you will need into account. Using a USB extender is often less expensive than using an active USB cable.
Most USB extenders are limited to USB 2.0. If you need to extend a USB 3.0 cable, using an active USB extension instead is the best option. Some USB extenders also come in the older USB 1.1 variant, which is slower than the modern USB 2.0. If data speed is a potential issue, keep the type of extender in mind when making your selection.