Get the Best Carabiner Shape for the Job

We could have made this blogpost one sentence: The majority of your non-locking carabiners will be Offset D shaped, while your locking carabiners will likely be Pear/HMS shaped for belaying and/or making anchor power points.

But why? We’ll discuss each of the 5 (+1) carabiner shapes in order from most available and popular to the least including best uses along with pros and cons. You’ll soon be able to tell the best shape for each area of climbing from belay to quickdraws to anchors. And you’ll be able to ignore some classic shapes until you delve into niche climbing styles like aid climbing (less than 1% of climbers).

*This graph shows each carabiner shape in terms of their share of the market (2023).*

Nerd Stats: The amount of Pear/HMS options have been increasing of late; in 2014 they made up only 22% of the options while today they make up 31.4% of the options. Ovals almost looked to be going extinct; in 2014 they made up a minimal 8%, but today they’ve had a comeback to 17.4% of the options. Offset D’s, which had been on a rocket ship trajectory to take over, were at 60% in 2014, but have decreased back to 42% of the market – as more Pear/HMS and Ovals options became available.

Offset D (aka Modified D) Carabiner

42% of the carabiner market, 250+ options click to see them all.

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offset D shaped carabiners — *DMM Alpha Trad, Mad Rock Trigger Wire, Mammut Element Keylock Straight and Bent, Kong Big D*

A slight modification of the standard D carabiner (described below); the top of an offset D carabiner is much wider, allowing for a larger (and superior) gate opening. When loaded, most of the weight is transferred to the spine of the carabiner which creates greater strength than most other shapes.

Pros

largest gate opening (providing the easiest clipping)
stronger than most other carabiner shapes (with weight directed to the spine)
lightest options (in part thanks to the narrow bottom)

Cons

generally more expensive than other shapes (more complicated to design/forge)
not as strong as standard D-shaped carabiners (D’s allow even more weight to be transferred to the spine)

Best Uses

top and bottom ‘biners on quickdraws (shape maintains the correct orientation on a quickdraw, high strength-to-weight ratio, and a large gate opening for easy clipping)
clipping into bolts or gear for multi-point anchors (similar to use on ‘draws)
racking cams on your harness (low weight and volume)

Price Range: $6 – $50

Weight Range: 19g – 250g

How Many Do you Need?

Sport Climber: Most likely all of your non-locking carabiners will be offset D’s. For an effective sport climbing rack you’ll need a minimum of 14 offset D’s used in 6 quickdraws (2 carabiners per quickdraw) and 2 carabiners for anchoring into bolts/chains. Depending on the length of routes you climb, you may want 20+ quickdraws (through 12 quickdraws is pretty standard starting out – especially if your partner has the same).
Indoor Climber: Most climbing gyms have permanent draws in place for lead climbing so you won’t be using any for personal quickdraws. If you climb exclusively indoors (top rope and/or lead climbing), the only carabiner that is required for leading is your belay carabiner which will likely be a Pear/HMS shape, so technically you don’t need any offset D’s. However, we’ve seen many folks use them for their chalk bag. Note: If your gym is pre-rigged with GriGri’s, an offset D locking carabiner is a fine option.
Trad/Alpine Climber: Most likely all your non-locking carabiners, including your alpine draws and racking carabiners, will be offset D’s to keep weight down. If you own cams and slings, we envision a minimum of 24 offset D’s but that number is entirely dependent on the number of pieces you own and will increase as your rack grows.

Bottom Line: The advances in forging technology have allowed this shape to be incredibly light and strong, making offset D’s the most common carabiner shape. Most of your non-locking carabiners, will be an offset D, especially since they dominate 60% of the market.

Pear / HMS Carabiner

31.4% of the carabiner market, 200+ options click to see them all.

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Pear HMS shaped carabiners — *Petzl Attache 3D, Black Diamond Magnetron VaperLock, Edelrid HMS Strike Slider FG, Edelrid HMS Magnum Twist*

Climbing culture uses the word Pear interchangeably with HMS. The Pear/HMS carabiner shape is used primarily as a belay carabiner or anchor power point. These carabiners are almost exclusively locking carabiners, and are essentially the hybrid combination of an offset D and oval.

Wikipedia defines HMS as an abbreviation for the German word “Halbmastwurfsicherung” meaning “half clove hitch belay” – or Münter hitch. The Münter hitch requires enough room on the carabiner to take two turns of rope while still being able to easily close the gate, which is the driving design criteria for these carabiners.

It’s easy to visually understand the pear shape, wide on one end and narrow on the other end. The pear shape can equally load the gate and the spine (particularly for the most classic pear shape) so like ovals, they’re not as strong as D/Offset D carabiners. That is why Pear/HMS shaped carabiners are generally heavier: they utilize more material to gain back the lost strength.

Some Pear/HMS shaped carabiners are a little offset. This allows them to be lighter by shifting some of the force to the spine.

Pros

large gate opening (easy to clip into)
lots of room for clipping multiple items (ropes, knots, slings, etc)
often have rounded rope-bearing surface for smooth belays and reducing rope wear

Cons

less strong than D’s/Offset D’s
heavier than most other shapes
price range starts higher as they use more material

Best Uses

belay carabiner (wide top reduces rope binding especially during rappel, larger rope-bearing cross section for smoother belaying and less kinking)
anchor power points (larger size allows for easier organization)

Typical Price Range: $11 – $40

Weight Range: 44g – 250g

How Many Do You Need?

Sport Climber: 1 for your belay device, perhaps another for an anchor powerpoint
Indoor Climber: 1 for your belay device
Trad/Alpine/Mountaineer: 2, one for belay, and one for your anchor powerpoint

Bottom Line: Although you can use Offset D locking carabiners to hold your belay device, history has made a Pear/HMS the most popular choice. One reason that a Pear/HMS is touted superior is: if you, unfortunately, dropped your belay device you could still use a Münter hitch to belay/rappel. Today many climbers don’t know how to tie a Munter hitch, so this is of little help. Often the Pear/HMS shape can sit better in your belay loop than an offset D, and particularly because when there is a rounded edge, it will provide a smoother belay.

Oval

8% of the carabiner market, 100+ models click to see them all.

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oval shaped carabiners — *Black Diamond Ovalwire, Cypher Oval, Mammut Oval Screwlock, CAMP Compact Oval Twistlock*

Ovals are Classic, they used to be the go-to workhorse and used for everything, before there were other shapes. Ovals were the first carabiner shape to be mass produced (in the US we thank Chouinard and SMC). Today, other than racking your nuts or aid climbing or as part of a rescue kit, most climbers don’t use ovals.

When loaded, the pressure is shared equally on both sides (spine and gate) of the carabiner. Since the weaker gate shares the load with the spine, oval carabiners aren’t as strong as offset D’s that direct the load to the stronger spine.

Pros

flips/rotates easily when unweighted, minimal movement while weighted
inexpensive

Cons

weaker than other shapes
smaller gate opening than most shapes
heavier than most shapes

Best Uses

racking your nuts (nuts spin around the curves easily, no catching points)
aid climbing (reduces shifting under load due to the symmetry)
to hold a pulley (the pulley will sit smoothly at the end)
best shape for a carabiner brake rappel system (not commonly used, but the symmetric shape is key)
straight spine for tying knots like a Bachmann knot

Typical Price Range: $9 – $35

Weight Range: 37g – 260g

How Many Do You Need?

Mountaineer: 1 for carrying your rescue gear (pulley, prussic, small knife), that could also be used to hold the pulley in crevasse rescue
Trad/Alpine Climber: 2-3, one for your rescue kit, the rest to rack your nuts/hexes/tricams
Aid Climbers: The sky is your limit
Sport Climber: If you climb multi-pitch and have a rescue kit, then use an oval to carry it (an oval can act as a pulley better than other carabiners in a rescue situation), otherwise, you don’t need ‘em
Indoor Climber: No need for an oval

D (aka symmetric D)

4.6% of the market, ~40 models click to see them all.

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D shaped carabiners — *Omega Pacific Lava, Black Diamond Light D, DMM Ultra D Screwgate, Petzl AM’D BallLock*

D’s continue to see a shrinking share of the market for rock climbers because offset D’s (or ovals) tend to be a better alternative. The classic D shape is symmetrical and naturally sets the rope closer to the spine, putting the load on the spine (versus sharing the load with the weaker gate side, like an oval). Since the strongest part (the spine) of the carabiner carries the weight, D’s are the strongest shape. This is also why safety industries, like search and rescue, still uses a more classic D shape.

Note: On WeighMyRack, we list some carabiners as D-shaped that we’d personally call an offset D. Since the manufacturer describes them as a “D” or “D-shaped” carabiner, and they’re close (and since there are no official rules on how symmetric the D-shape actually is), we let it slide and call it a D.

Pros

strongest shape
larger gate opening than ovals
lighter than ovals and Pear/HMS shapes

Cons

slightly more expensive than ovals
smaller gate opening than Offset D’s
heavier than Offset D’s

Best Uses

You’ll find D’s don’t really have an exclusive use but there are times when they can be helpful.

second best style for carabiner brake rappels (not commonly used, but the almost symmetric shape is key)
best shape (like oval) to tie a Bachmann knot (thanks to the straight back)
anchor power points (piece of mind with maximum strength)

Price Range: $5.95 – $31.30

Weight Range: 43g – 280g

How Many Do You Need?

Wiregate/Solid Gate D’s: None. There’s no best use for a D shape carabiner. If you have some, you can use them for anchors, or for aid climbing, or to hold your rescue kit. They’re strong, but their shape doesn’t make them excel in any particular area.
Locking D’s: You could use one on an outdoor multi-pitch climb… though generally the offset D’s lockers will be even lighter if you don’t want the weight of an HMS/Pear.

Bottom Line: There’s no incredibly compelling reason to purchase traditional D shaped carabiners. Historically they were an improvement upon ovals as they were significantly stronger. But with the development of the Offset D, the standard D quickly became less desirable. D’s used to be substantially less expensive than other shapes, but manufacturers have been able to lower the price for all carabiners (think: more efficient forging, and offshoring) so D’s no longer have a significant price advantage.

Oval Link (aka Quicklink, Maillon)

1% of the carabiner market, ~15 models click to see them all.

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oval links mallons quicklinks — *Cypher Steel Link, Petzl Go, CAMP Oval Quick Link, Grivel Maillon Raptide, Omega Pacific Screw Link*

Although most climbers wouldn’t refer to this shape as a “carabiner” they are certified by the same EN standard as all the other carabiners. These semi-permanent links ensure the gate will not accidentally open. They are not used while climbing up, though they can assist when setting up a semi-permanent rappel station or on fixed quickdraws.

Pros: small and inexpensive

Cons: infrequently used (no need to carry extra weight for most climbers)

Best Uses: rappel stations (nature-based or bolted anchors)

Note: Non-Climbing brands make these types of links as well, if you’re buying from a non-climbing brand, make sure it is certified EN12275

Price Range: $3 – $12

Weight Range: 21g – 151g

How Many Do You Need?

Most climbers: None.
Alpine/Trad/Mountaineering: If you’re setting up your own anchors, and rappel stations (say around trees) this can be helpful so you don’t rappel on webbing alone. These links are lighter than rappel rings.
Sport Climbers: None. If you saw a super worn out chain link, you could add an oval link to act as a stronger chain link for a safer rappel (not a common practice).

Bottom Line: The only common use is in anchor situations. If you do not set up rappel anchors/improve rappel stations, particularly in the alpine, then there is no need to carry ’em.

Semi-Circle Carabiners

Less than 1% of the market, we only catalog four options.

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3d and semi circle carabiners — *Petzl Omni Screw-Lock, Petzl Omni Triact-Lock, Stubai HMS 3D*

Semi-Circles: In rock climbing, these carabiners are best paired with a chest harness or full body harness. Buy if you need to secure a chest harness where you would end up cross-loading any “normal” shaped carabiner.

These carabiners are most used in professional settings, as they are typically required to wear a chest/full body harness.

Price Range: $40 – $70

Weight Range: 84g – 92g

Summary

In the most broad sense, you could grab most any carabiner and use it in most any circumstance. A climber could still climb hard even if their rack was exclusively ovals or D’s. However, you may be disappointed in the performance, especially if you’ve ever experienced using a carabiner specifically designed for the purpose you’re using it for.

Choosing the best carabiner comes down to knowing what job you want your carabiner to do. Is it going to primarily be for clipping bolts while sport climbing or racking nuts while trad climbing? Will you be using it for a belay carabiner or to make anchors? And, what’s your budget?

Each carabiner style has (or had) a purpose and a scenario where it performs better than any other shape – though that difference usually only matters in niche situations, like racking your nuts as a trad climber, or holding aiders as an aid climber.

So, the bottom lines are similar to the top line: The majority of your non-locking carabiners will be Offset D shaped, while your locking carabiners will likely be Pear/HMS for belaying and/or making anchor power points. Offset D locking carabiners can be a lighter alternative and will work well with mechanical belay devices but don’t tend to work well with traditional tube style devices or newer tube style brake assist devices).

Alison Dennis

Alison (she/her) runs WeighMyRack from her 17' travel trailer. She is currently touring the US and would love if you contacted her to meet up to talk about climbing, climbing gear, or if you have any fun and/or ridiculous adventure in mind.

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