A guide to Carabiners

Rack Of Carabiners Crop 1

By Mike Hawkins

There are a wide variety of carabiners available on the market, and each type has its pros and cons. Some carabiners are built for very specific uses, while others are geared toward general use. For both safety and efficiency, it is worthwhile to understand the subtle differences in order to choose the right carabiners for your climbing objectives. 

Locking vs. Non-Locking


Locking carabiners should be used in any situation during which an open gate could lead to injury or system failure. 

The main benefit of a locking carabiner is that it can be trusted to keep the rope and other safety equipment safely inside its clutches, regardless of items pressing or banging against the carabiner. In certain circumstances, two locking carabiners facing opposite directions are preferred, especially when a lot of continued movement or usage is expected over time without inspection. For instance, climbers often double up on locking carabiners when walking on a rope team in mountaineering, as the movement of the rope can untwist a single locking carabiner over time. 

carabiner comparison
Autolocking HMS, Full-size screwlock, Mini screwlock, D wiregate, Oval wiregate, and mini D styles.


  • Screwgate: These are the gold standard of locking carabiners. Screwgate lockers are simple, lightweight, and easy to use. They are easily manipulated with a single gloved hand. Screwgate carabiners are the best choice for nearly all general climbing needs.**One helpful feature to look out for on some screwgate carabiners is a thick red line on the gate above the threads. This simple feature is intended to alert you that your carabiner is not locked.**
  • Auto Locking: Once you master the opening mechanism, auto locking carabiners are fast and consistent. Most auto locking designs allow carabiners to be opened and closed in a fraction of the time it takes to do the same with a screwgate carabiner. The niche auto locking feature is especially useful when repeatedly clipping in and out of protection, ensuring your carabiner is locked each time it is moved.


  • Anti Cross-Loading: These locking carabiners have been specially designed for use with belay devices. Each has a normal gate opening with two ‘zones’ inside, separated by a small gate feature. The zonal separation traps the carabiner in place on your belay loop while belaying; this eliminates the possibility of the carabiner turning sideways into its most dangerous configuration, where it could be loaded along the gate at its horizontal axis.
Carabiners vary greatly in size and style. Here, a mini wiregate and a full-size autolocking HMS


Non-locking carabiners are lightweight and versatile and should be used in tandem with other carabiners when an open gate would not lead to injury or system failure.

If locking carabiners are so great, why do we even bother with non-lockers? Non-locking carabiners are more efficient for quickly attaching things to our harness or attaching ourselves to climbing protection. They also have the benefit of generally being lighter-weight and lower volume, which is crucial for stacking lots of equipment onto a few small harness gear loops. 


  • Solid Gate: Burliest of the non-lockers, solid gate carabiners are versatile and durable. These are a little heavier than the other styles, but many come standard with a smooth, keylock nose to keep your carabiner from snagging when clipping and unclipping. This is a good all around carabiner for general use, but wire gates tend to offer climbers more benefits.
  • Wire Gate: This is the gold standard of the non-lockers. Wire gates are lighter than their solid gate cousins, and there are numerous options to choose from. The very lightest of the bunch are plenty strong, but they tend to wear out a little quicker than heavier models. Wire gates are also less prone to freezing shut in cold, snowy conditions than solid gates.
  • Mono Wire: Racking all of your gear with these might break the bank, but they are a fantastic option for advanced climbers looking to save even more weight. Mono wires are wire gate carabiners with only a single wire as the gate. The single wire snaps shut inside the nose of the carabiner, offering the same keylock nose benefits of a solid gate carabiner. As always, lighter weight equipment typically means flexing a bit on long-term durability.


standard nose
standard nose
keylock nose

Size and Shape

Each carabiner type comes in a variety of shapes and sizes. Large carabiners more easily accept clove hitches, large diameter fixed lines, and large amounts of gear, but they are heavier, bulkier, and more difficult to clip into smaller spaces. Meanwhile, small carabiners can be clipped into small spaces, are super light, and take up very little space on a harness gear loop. However, the smallest carabiners don’t have enough space for clipping into with a clove hitch, and they can be hard to manipulate, even with bare hands. 

  • Asymmetric D: Wide gate opening; great all around option; good for using with a personal anchor, clipping in for mountaineering, or clipping to a fixed line
  • Pear: Wide gate opening; good for belaying and rappelling
  • D: Medium gate opening; small amount of clipping space; good for use with hauling systems and clipping to climbing protection
  • Oval: Small gate opening; plentiful clipping space; good for using with ascenders and personal tethers

In summary, it’s probably not all that useful to own a set of ten D-shaped, auto-locking carabiners. Most climbers will be well served by a number of various asymmetric D screwgate and wiregate carabiners. Having a few niche carabiners for specific purposes also makes a lot of sense, especially for use on more challenging climbs. 


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