What is the best locking carabiner for rock climbing in 2019? We compared 15 of the best locking carabiners in a variety of tests to find out. We judged each carabiner on the following six categories: lightness/compactness, ease of unlocking, gate hang up, amount of knots held, rope pull smoothness, and gate clearance. In the end, we found that there was no one product that excels at everything. Instead, there are three main categories which each had their own top products: lightweight locking carabiners, medium belay, and rappel carabiners, and large belay and rappel carabiners.

Best Overall Locking Carabiner: Petzl Attache

Petzl Atache Lock Carabiner
The Petzl Attache is our top choice among all the locking carabiners we reviewed.

Our choice goes to the Petzl Attache. It was the only carabiner to score high in every category and the only light carabiner to really excel in the overall scores. This carabiner excels at just about everything. Its main drawback is the price.

Best Value: Black Diamond RockLock

Black Diamond Rocklock Locking Carabiner
The Black Diamond RockLock which scored very well in most categories except for being light and compact

The Best Value goes to the Black Diamond RockLock which scored very well in most categories except for being light and compact. It was not only a top scorer, but it was also among the cheapest carabiners at $10-12. We also have a Great Value award to the Mad Rock Super Tech Keylock Screw which is the carabiner we would load up on if we were on a budget.

Best Lightweight: Mad Rock Super Tech Keylock Screw

Mad Rock Super Tech Keylock Screw
A great value buy, the Mad Rock is our choice as the best lightweight biner

The Mad Rock Super Tech was our favorite ultralight biner. Since we are obsessed on all things light, we would probably just buy these and the Petzl Attache if we had an unlimited budget.

How We Chose

Lightness and compactness

Our favorite lightweight locking carabiner was the Mad Rock Super Tech which edged ahead of the other two super light carabiners: the Wild Country Ascent HMS and the Trango SuperFly Screwlock.

Which was the lightest?

It’s hard to say because the manufacturer weight listings were a little different than our own measurements. They are all within a few grams of each other with the Trango being a little lighter than the Mad Rock. The Mad Rock is our top pick because it had the smoothest keylock gate, was really easy to handle and just looks cool. If we were on a budget, we would go with Mad Rock as our main choice. The Trango is a solid biner but we prefer the keylock gate of the other biners. It was also the most expensive of the three.

Another notable light biner is the Petzl Attache, which is not as light as these three but is probably the lightest considering its size. With most light biners, the small size means you sacrifice a little in the range of activities the carabiner is good for. That is why the light biners, in general, score lower. They just don’t do a lot of functions as well as bigger locking carabiners. The Petzl Attache, on the other hand, is very light and very functional across a wide variety of tasks.

Ease of Unlocking and Locking

The DMM Boa Quicklock was the easiest carabiner to lock and unlock. The twist lock is incredibly smooth and the shape of the carabiner makes it very easy to lock and unlock. In general, all the twist-lock carabiners were easier to lock and unlock than the screw gates. As far as screw-gate carabiners, there were five carabiners that all tied for best. The Petzl carabiners stood out for having bigger twist gates that were easy to use, especially with gloves. The DMM Boa Quicklock stood out for taking just one accurately placed twist to completely unlock (this probably only works with the carabiner is new and smooth).

Gate Hang Up

All the keylock carabiners did great in these tests which involved seeing how easily the gates got hung up on bolt hangers and slings with unclipping. It’s hard to single out a clear winner in this category. The clear low scorers were the non-keylock carabiners. We would still use a non-keylock carabiner, but we really prefer the keylock feature.

Number of Knots Held

The DMM Boa and Black Diamond Rocklock got top scores for holding the most knots and slings. These are great locking carabiners to use as the “master point” of an anchor because you can easily clip multiple knots on a bite, slings and other items. The Petzl carabiners and the Black Diamond Mini Pearabiner also scored very high. Not surprisingly, the worst scores came from the lightest and smallest carabiners. The exception was the Petzl Attache 3D which is very light but still scored well for holding many knots and slings.

Rope Pull Smoothness

The best carabiner for pulling the rope over was the Petzl Attache. It has a wide diameter and is almost perfectly round which makes the rope pass over with minimal friction. It is no surprise this is the carabiner most guides use when belaying a second in auto-block mode from the anchor. The Petzl Attache 3D scored nearly as well and is much lighter. Many other carabiners scored high and would make great belay carabiners. The super light mini carabiners scored the world.

Gate Clearance

The Black Diamond Rocklock and Omega Pacific Jake scored the best for gate clearance but there were many other carabiners close behind. The carabiners with the worst gate clearance were the small lightweight carabiners.

How to Choose the Best Locking Carabiner for You

Locking carabiners have evolved a lot in the last decade. They are lighter and are designed for more specialized tasks. There are few one-size-fits-all carabiners. Instead, there are certain carabiners that are best for belaying, rappelling, use in anchors and lightweight biners. Below, we look at key factors to use when choosing the best locking carabiner. – Chris McNamara

Lightness, Compactness

If you just are buying a carabiner for belaying at the gym or the crag, weight does not matter much. If you are climbing multi-pitch routes or doing alpine routes, every ounce is crucial. The difference between having six light locking carabiners on your harness or six standard locking carabiners is big. More importantly, light biners are much less bulky so they swing around less on your harness and don’t get stuck as much in chimneys. The good news is there are more lightweight carabiners than ever. The challenge is finding a carabiner that can do everything you need at the right price. Most light biners work fine for general use, but do not excel at belaying, rappelling or use as a master point in an anchor due to their small size. You lose some functionality with most light carabiners so make sure the weight saving is worth it. We discovered that the manufacturer’s quoted weight and the weight from our scale can differ by as much as five percent. This doesn’t mean you should trust our weight more than the manufacturers. But it does mean you should not get hung up on a few grams of difference when buying a light carabiner.

Gate Type: Screw-gate or Twist-lock?

There are two main gate types: twist-lock (or quick-lock) and screw-gate. A twist-lock carabiner is the fastest to lock and unlock because you can take it off and on with just one motion of your hand. For this reason, they are ideal for gym climbing or cragging if you want to save time. The screw-gate carabiners take more turns to close and you must remember to close them (twist-lock carabiners have a spring and close on their own). However, a screw-gate carabiner can feel more secure in an anchor because it is less likely that the gate can open accidentally if the carabiner is moved into an awkward position. This problem is addressed in some carabiners that use a ball-lock mechanism like the carabiner below.

Screw-gate carabiners are usually 25 percent less expensive and lighter in weight. In general, twist-lock carabiners are best for belaying and rappelling and screw-gate carabiners are better for everything else.

When buying a screw-gate carabiner, consider how many twists it takes to open and close the gate. We generally prefer biners that take fewer twists because you save time. However, some people may feel safer if a carabiner takes more twists to open and close. Also, when carabiners are brand new, some gates will be more fluid. Some biners can be opened and closed with one precise flick of the fingers, which is convenient.

Because you have to remember to close a screw-gate carabiner, it’s nice to have safety features as Petzl uses. They have a red stripe that disappears when the gate is closed. This helps remind you to lock the gate and also helps prevent over-tightening. Other manufacturers deal with the over-tightening issue by putting metal on the gate so that the gate stops the screw-gate mechanism before it hits the other side of the biner.

Gate Hangup

We prefer key-lock gates because they get hung up less on slings and bolt hangers. Most carabiners now come with key-lock options and they generally don’t cost more so there is no reason not to go the key-lock route. In addition, some key-lock carabiners are a little smoother to get on and off due to the angle of their key-lock; the smoother the angle the smoother the carabiner comes on and off. However, that is a pretty subtle distinction between key-lock carabiners. The main thing is to go key-lock when possible.

Number of Knots Held

If you use a carabiner in an anchor, especially as the master point, it’s nice if the biner holds lots of ropes and slings. Generally, the larger the carabiner, the better it is at holding lots of cord. That said, the shape also plays a role. If a carabiner has a pear shape with a big area below the gate, then more ropes and slings will fit in. A D shape or oval shape generally holds a little less. Lightweight carabiners hold very few ropes and slings because of their compact size, which limits their versatility.

Rope Pull Smoothness

How smoothly a rope pulls through a carabiner is essential if you are belaying a second climber off the anchor using an auto-block belay device like the Petzl Reverso 3. The wider and rounder the stock of the aluminum, the smoother the rope will flow over it. In addition, carabiners with more oval shapes or pear shapes generally keep the rope from contacting the spine and therefore have less drag. The other instance where rope pull smoothness is nice is with top rope anchors, where it is nice to have a smooth pull. Other than those situations, smoothness is less important compared to other factors like the gate performance, shape and weight.

Gate Clearance

We found gate clearance to be less important than how many ropes a biner will hold. In general, you are only clipping one rope or sling at a time and all gates work about the same. Only in very specialized applications like using a locking carabiner with a big pulley is gate clearance as big an issue.