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:

1. Understanding Carabiner Strength Ratings
2. Types of Carabiner
3. Carabiner Weight: Does it Matter?
4. 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 original 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.

Types of Carabiner

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.

How To Choose the Right Carabiners

Ultimately, the carabiners you select will reflect your personal needs and preferred style of climbing. Here are some sample shopping lists to get you started.

Gym Climbing

• 1 auto-locking HMS carabiner for belaying
• 1 wire-gate carabiner to hold shoes or other gear on a harness

Top-Roping

• 1 auto-locking HMS carabiner for belaying
• 2 HMS carabiners and 2 smaller locking carabiners for a top-rope anchor
• 1 wire-gate carabiner to hold shoes or other gear on a harness
• 1 auto-locking carabiner for a personal tether

Sport Climbing

• 10 to 15 quickdraws with one solid-gate carabiner and one bent-gate carabiner each
• 1 auto-locking HMS carabiner for belaying and rappelling
• 1 auto-locking carabiner for a personal tether
• 1 auto-locking carabiner for a friction hitch backup
• 1 wire-gate carabiner to hold shoes or other gear on a harness

Traditional Climbing

• A full rack of cams with one small wire-gate carabiner each
• 10 to 12 extendable alpine draws with two non-locking carabiners each
• A full rack of nuts on a solid-gate oval carabiner
• 1 auto-locking HMS carabiner for belaying
• 1 auto-locking carabiner for rappelling
• 1 auto-locking carabiner for a friction hitch backup
• 1 locking carabiner for a personal tether
• 1 spare locking carabiner for building anchors
• 3 spare non-locking carabiners to hold webbing, slings, or cordelette on a harness

All articles are for general informational purposes.  Each individual’s needs, preferences, goals and abilities may vary.  Be sure to obtain all appropriate training, expert supervision and/or medical advice before engaging in strenuous or potentially hazardous activity.