What Is a Carabiner and What Can I Do With One?

If you’ve kept up with any part of the outdoor news in the last couple of years, then you’ve likely noticed that previously fringe outdoor sports are on the upward swing in popular culture. With the mainstream rise of documentaries like Alex Honnold’s “Free Solo” and cult-classic films like “Valley Uprising,” the outdoor world has experienced somewhat of a Renaissance, and with it has come a slew of new and interested enthusiasts.

Unfortunately, too often the outdoor world can be a place where the lingo, the gear and the wealth of experience of the pros have served as an obstacle to those looking to learn and engage on a beginner’s level. In the world of outdoor sports, things like climbing, backpacking, and kayaking can feel like exclusive clubs reserved for those who already know and understand the language. But the reality is, those are all just different outdoor activities, open to anyone who is willing to give them a shot.
Here at The Dyrt, we’re working to open the outdoor world to everyone, one campground review at a time. To help with that, we’ve created this quick overview of one of the most important tools in the outdoor world: the carabiner.

Although commonly found in everyday life, the carabiner’s true functionality is on full display during a variety of outdoor sports.

If you’ve never had the chance to use one, things can get pretty confusing. Is it for climbing? For hanging on? For attaching things? For holding your water bottle? The answer is yes, but it’s a bit more complicated than that.

Generally speaking, the carabiner is a coupling link with a safety closure, meaning it’s basically a tool that’s designed to keep you safe, consisting of a curved body with a straight or curved bar known as the gate that opens and closes.

The locking or closure mechanism on every carabiner is meant to allow for things to be attached to it without the fear of them coming off. Unlike a traditional coupling link, which has no closure point, carabiners offer easy clipping ability and a secure waypoint for whoever might need one.

That said, there are a few different kinds of carabiners, each of which has a slightly different use.

This is the carabiner we’ve all attached to our keys at one point or another. It’s called a wire carabiner because the locking mechanism is a wire loop that usually hooks onto the nose of the carabiner. (The nose of the carabiner is the place where the gate opens and closes). This is the carabiner you might be picturing if you’ve never gone climbing or used one in an industrial setting.

These carabiners are meant to be convenient devices for keychains, water bottles and minor household uses. They can be great for car campers in a pinch who need to hook a rain tarp to their shelter or for tenters needing a way to carry all of their gear, but they’re not ideal for holding much more than your supplies.

These types of carabiners have what’s called an open-lock safety closure, meaning all you have to do is press on the straight edge of the carabiner to get it to open. While safe in terms of keeping a tarp secure, they aren’t safe enough to hold your body weight. They should never be used during activities such as climbing, where your gear plays a large role in determining the level of safety you experience on the wall.

That said, keychain carabiners can be a fun way to carry the outdoors with you wherever you go, and they can be used in a variety of low-stakes situations to make things easier.

A “straight gate” carabiner is a style of carabiner that can be opened with pressure alone. Straight gaters are known for being easy to latch and operate on the go. Heavier duty versions of this carabiner can be used for climbing, particularly for hooking into a bolt, where the chances of accidental release of the locking gate are slim.

Straight gate carabiners are also found in sports like backpacking or kayaking, where the carabiner is relied upon for simpler duties, like hooking into a dock line or attaching a sled or tool to your pack. The straight gate style of carabiner can be seen as a semi-happy medium between the heavy duty wire gate carabiner and the wire carabiners that frequent keychains and outdoor shows.

The Bent Gate Carabiner

Like a straight gate carabiner, bent gates are exactly what they sound like: carabiners with a gate that’s slightly curved. While not as frequently seen in the outdoors, these carabiners are primarily used by climbers, as the bent gate carabiners receive rope much more easily than the straight gates. The curve in the gate allows for extremely quick hook-ins, which can be vital as climbers make their way up the wall.

The Twin Gate Carabiner

A relatively recent invention, the bent gate carabiner is an interesting medium between locking carabiners and straight gaters with no lock. These carabiners have two gates that open on opposite ends, creating a sort of lock that requires special pressure to open. While not widely used, they are effective in situations that call for a bit of extra safety; some climbers or outdoor enthusiasts actually prefer them to traditional straight or bent gate carabiners.

While not necessarily a “type” in itself, the locking carabiner is the carabiner most widely used in outdoor sports, climbing in particular. These carabiners have a gate that’s reinforced by a locking mechanism, which secures the carabiner in its closed position and ensures absolute safety.

Since it requires a double motion to open, these carabiners are ideal for setting up climbing gear and securing kayaks or boats to way-points without the fear of an accidental release. That said, for quick transfer mid-climb, these carabiners are not as quick to open as a straight or bent gate with no lock.

Types of Locks:

Locking carabiners often come in three different varieties.

Screw lock: In screw lock carabiners, a metal cylinder must be screwed up to cover the nose once it’s in place or down to allow the carabiner to open.

Twist lock: These auto-locking carabiners have a spring-loaded cylinder that allows the carabiner to open when it is twisted into a certain position. As soon as the carabiner closes, the cylinder springs back into position to lock the carabiner into place.

Magnetic lock: The least commonly used of the locking carabiners, these have magnets on each side of the nose to keep the carabiner locked when it’s closed. It can only be opened when pressed on both sides, which releases the magnets from the gate.

Buying your first carabiners as a new climber can be deceptively complicated. There are dozens of types of carabiners out there, each with slight differences in shape, size, and weight. These factors make them well-suited to certain uses and a poor fit for others. Here’s what you need to know to choose the right ones. 

Here’s what this guide covers:

Understanding Carabiner Strength Ratings

Types of Carabiner

Carabiner Weight: Does it Matter?

How to Choose the Right Carabiners

Understanding Carabiner Strength Ratings

All carabiners that are safe to use for climbing must receive a European Conformity (CE) and/or Union Internationale des Associations d’Alpinisme (UIAA) strength rating. You’ll see those ratings on the spine of a carabiner—the three numbers indicate how much force the carabiner can take in a lengthwise direction, a cross-loaded direction, and while open. 

You’ll see different numbers on different carabiners, but all of them are tested for strengths that vastly exceed what a climber could produce in a fall. Any UIAA- or CE-rated carabiner is safe to use for climbing as long as it’s closed and loaded in a lengthwise direction. The only time you might want to consider the strength ratings is if you’re considering two carabiners with the exact same price, weight, and functionality and are looking for a tie-breaker. 

Any carabiner that’s not marked with a rating, or is labeled “Not for Climbing,” should never be used in a technical climbing application.

Carabiner Shapes

One of the first things you might notice about carabiners is that they come in a variety of shapes. Each one has its pros and cons.  

Oval Shape

Oval-shape carabiners are symmetrical with a semi-circle curve at the top and bottom. This is the twist lock carabiner shape; they’re inexpensive, and their wide curves mean they can hold a lot of gear and accommodate a variety of hitches. However, they can be a pain to clip while lead-climbing because it’s hard to tell at a glance if they’re upside-down or right-side up. Another con: oval carabiners tend to be heavy.

D Shape

This is the strongest shape of carabiner out there and one of the most versatile. Tapering funnels gear toward the spine of a D-shape carabiner. That and the wide gate opening make them easier to open and close than oval-shape carabiners. However, like ovals, they tend to be on the heavier side.

Asymmetric D Shape

These are essentially D-shape carabiners but with one smaller tapered end, which helps reduce weight and provide a wider gate opening than conventional D-shape or oval-shape carabiners. Because they’re strong, lightweight, and versatile, asymmetric D-shape carabiners are very popular. The only con: They also tend to be pricier than other versions.

Pear Shape or HMS

There are lots of carabiner shapes out there, but the classic pear-shape carabiner is notable for its big gate and wide, rounded top edge, which easily accommodates hitches, belay devices, and plenty of gear. It’s often called an “HMS carabiner” because it’s sized to accommodate a belay hitch called a Munter hitch, or Halbmastwurfsicherung (HMS) in German. 

Because they’re big and heavy, locking HMS carabiners tend to be overkill for many uses. However, they make great belay and rappel carabiners, and their ease of use makes them a good choice for setting up top-rope anchors.

Locking Carabiners: Locking carabiners have a failsafe mechanism to keep them closed—usually a metal tube you can twist to shield the gate from opening accidentally (the gate is the part of the carabiner that opens and closes). They’re ideal for building anchors, rappelling, belaying, and any other situation where accidentally unclipping could put your life in danger. They’re more expensive and heavier than non-locking carabiners.

Non-Locking Carabiners 

Non-locking carabiners are easy to snap open and shut. Because they lack a locking mechanism, they tend to be lightweight. These are ideal for sport-climbing quickdraws, storing trad (traditional) gear on your harness, and other applications where ease of use is paramount and other measures—like multiple bolts or pieces of gear—are there to protect you in case of an accidental unclip.
Auto-locking carabiners

While the most common locking carabiners must be manually screwed shut, some models include spring-loaded locks or magnets that lock them automatically. That provides one extra level of protection against accidental errors. Auto-locking carabiners can take a little time to get used to, but they are great options for belaying, personal anchor systems, and rappelling. 

Wiregate versus solid gate

Most carabiners have a solid metal cylinder for a gate, but wiregates substitute that with sturdy stainless-steel wire, which saves weight and makes the carabiner less likely to freeze shut. Most receive comparable strength ratings to straight-gate carabiners, though they’re more prone to losing their spring action over time and may need to be retired earlier than solid-gate carabiners.

Straight gate versus bent-gate

Most solid-gate carabiners have a cylindrical “straight gate,” though some gates feature a slight curve. The curve of a “bent gate” makes it easier to push the rope into the carabiner while clipping. Both straight- and bent-gate carabiners are strong and durable, but since the bend reduces the interior space of the carabiner, bent-gate carabiners are usually reserved for the rope end of quickdraws.

Carabiner Weight: Does it Matter?

The less weight you can carry up a climb, the stronger and faster you’ll feel. But while lightweight carabiners are plenty safe for nearly all climbing applications, they tend to be smaller and therefore harder to use. And because they’re thinner, sawing a rope over them can result in more wear and tear to your rope. They’re also less durable and can bend if they get trapped against the lip of an overhang under severe, repeated forces. For that reason, most climbers prefer a mix: small, lightweight carabiners for things like storing extra webbing slings or pieces of trad gear on a harness, and big, heavy carabiners for things like belaying.