Are you looking to buy a new belay device but aren't sure which one to choose? After researching over 30 models available on the market today, we have selected 15 of the best and most popular, spanning every style of device you could want, and put them through the wringer testing them head-to-head. We fed out miles of slack, lowered countless climbers, whipped once or twice (yeah right!), and watched heaps of YouTube videos trying to master new belay techniques, all in order to bring you the best possible recommendations for your climbing needs and adventures. Whether you are a new climber just starting out, simply curious about the newest gadgets, or a grizzled veteran replacing worn out gear, read on to learn which are the very best climbing belay devices.
The Best Climbing Belay Devices of 2019
|Price||$132.85 at Amazon|
Compare at 3 sellers
|$86.45 at Amazon|
Compare at 3 sellers
|$99.95 at REI|
Compare at 2 sellers
|$23.96 at Backcountry|
Compare at 3 sellers
|$29.95 at REI|
Compare at 3 sellers
|Pros||Anti-panic handle, top rope and lead modes feed smoothly, wide range of rope diameters (8.5 - 11mm)||Easy catch and hold, feeds slack smoothly, smooth lowering, handles ropes down to 8.5mm||Compact, safe and ergonomic way to pay out slack, a bit less expensive than GriGri||Great for belaying seconds on multi-pitch climbs, durable, good value||Lightweight, easy to unlock, great for belaying two skinny ropes|
|Cons||Expensive, switching modes can be annoying, panic handle locks up easily||A bit clunky, can only use one rope, takes time to master techniques||Method of clipping to harness is counter-intuitive, unlocking device under tension takes some practice, easy to lower too quickly||Heavier than the Reverso||Softer aluminum seems less durable, not ideal with ropes thicker than 9.5mm|
|Bottom Line||Excellent assisted braking belay device for both beginners and experienced users.||The gold standard remains the best and most popular belay device available today.||Behind the GriGri and +, this is the second best active assist braking device that we have used.||The best belay device for multi pitch climbing, rappels, and double rope ascents.||A match made in rock heaven for skinny ropes and climbers counting weight.|
|Rating Categories||Petzl GriGri+||Petzl GriGri||Trango Vergo||Black Diamond ATC Guide||Petzl Reverso|
|Catch And Bite (30%)|
|Lowering And Rappelling (30%)|
|Feeding Slack (20%)|
|Weight And Bulk (10%)|
|Auto Block (10%)|
|Specs||Petzl GriGri+||Petzl GriGri||Trango Vergo||Black Diamond ATC...||Petzl Reverso|
|Style||Active assisted braking||Active assisted braking||Active assisted braking||Auto-block tube||Auto-block tube|
|Recommended Rope Diameter||8.5 mm - 11 mm||8.5 mm - 11 mm||8.9 mm - 10.7 mm||7.7 mm - 11 mm||7.5 mm - 11 mm|
|Weight (oz)||7.1 oz.||6.3 oz.||7.1 oz.||2.8 oz.||2.2 oz.|
|Double Rope Rap?||No||No||No||Yes||Yes|
|Belay off anchor?||Yes||Yes||Yes||Yes||Yes|
|Warranty||3 year||3 year||1 year||1 year||3 year|
Best Overall for Experienced Climbers
In 2019, Petzl has updated the most popular assisted braking device in the world for a third time, releasing the newest version, now simply known (once again) as the GriGri. For those who are confused, this device updates the GriGri 2, which is no longer being produced or sold, but is not at all the same as the original GriGri, which it shares the same name with. Although it looks very similar to its predecessor, this new GriGri has seen a number of minor tweaks, often incorporating aspects that were found to be successful with the release of the GriGri+ in 2017. The cam spring is a bit tighter, making it easier to pay out slack ATC style, and the area on the back of the cam where you might hold your thumb to pay out slack is now lower profile as well, reducing the risk of holding this open when a leader falls. The lower arm now has a bit more play, making it slightly harder to simply open full. Best of all, this device now accommodates ropes down to 8.5mm, which is currently the skinniest single rope on the market. These tweaks are minor, but positive changes, that only make this device function better, although longtime GriGri 2 users will hardly notice the difference.
While the GriGri is far and away the most popular active assisted braking device on the market, it still comes with the notable downside that one must lock open the braking cam with the thumb to quickly feed slack to a leader, a design that has inspired countless competitors. With this model, it is easier than ever to "push" rope through the device, in the same way slack is fed with a tube style device, although the cam must till be overridden to feed out an armload or two in a hurry. Which brings up another downside of the GriGri — proper and safe belay techniques can be challenging to learn and perfect. Most of us who have been climbing for a couple years or longer have long since crossed this hurdle, and for them, we still recommend the GriGri as the best belay device on the market. For those who are new to climbing or inexperienced with a GriGri, or who simply like having even more safety features, we recommend the GriGri + instead.
Read review: Petzl GriGri
Best Overall for New Climbers or Those Who Want Extra Safety
First released in 2017, the GriGri+ has a number of safety features not found on the standard GriGri, hopefully reducing the risk of belayer error accidents. This device works in the exact same way as the GriGri, but also includes a couple of clever over-rides for the most common errors amongst GriGri users. The first is that the handle has an anti-panic feature. When lowering a climber, the belayer uses a lever-arm handle to release the grip the cam in the device has on the rope. It is possible to open this handle way too far, without a hand on the brake rope, and suddenly drop the climber to the ground. With the GriGri+, the handle automatically clicks open further beyond a certain point, releasing the tension on the cam, and stopping the lower. The sweet spot for a smooth, not too slow lower can be hard to find at first, but it is now much harder to drop a climber while lowering with a properly loaded GriGri+. The second feature is a toggle switch between lead and top-rope modes which adjusts the spring tension on the cam inside the device. In top-rope mode, the cam grips far more tightly, while in lead mode it allows for an easier time paying out slack.
While significantly safer than a standard GriGri, the features found on the + can be annoying to work around if you are so used to using a GriGri that it has become an extension of your mind and body. In particular, it is easy to forget to switch from top-rope to lead, resulting in a frustrated leader as they get continually short-roped. The new features also don't eliminate the need to lock out the cam while feeding out slack to a leader, a potentially dangerous moment, especially close to the ground. And the biggest hurdle to usage of the GriGri + is that it can be difficult to learn to use properly and safely, an argument many die-hard ATC users cite as the reason they avoid the GriGri to begin with. This model is also heavier and more expensive than the standard model. While there are some downsides, GriGri's have become nearly ubiquitous at the crag or in the gym no matter where in the world you are, and offer tremendous advantages over standard belay devices. We believe that all types of climbers can benefit from knowing how to use a GriGri, and recommend the + especially for those new to the game.
Read review: Petzl GriGri+
Best Bang for the Buck
Black Diamond ATC XP
Despite the ubiquity of active assisted braking belay devices these days, it is still essential to have a standard tube-style belay device. In our testing, the Black Diamond ATC XP came out on top for this style of belay device. For new climbers it is the most commonly taught and easiest to master belaying technique, and these devices are also far and away the most affordable. This device has two friction channels that include toothed grooves to improve friction and offer superior braking strength when catching a lead fall. These devices are also versatile for doing double-roped rappels, and indeed are necessary if that is your intent for the day!
Compared to its closest challenger, the Petzl Verso, the ATC XP is slightly heavier (0.2 ounces), and the Verso can accommodate a slightly thinner rope (7.5mm vs. 7.7mm). The Verso even retails for less, however, we preferred the ATC XP because it's slightly more durable and has stronger lock-off friction. They're both great devices though, so look for deals and consider whichever one is on sale.
Read review: Black Diamond ATC XP
Best Buy for an Assisted Braking Device
Mammut Smart 2.0
Passive assisted braking devices are experiencing a bit of a renaissance these days, with Black Diamond releasing a new model (the ATC Pilot) and Mammu* updating their Smart 2.0 model. Both devices are one-strand only models that work well for single-pitch leading and top-roping. They're called "passive" devices because there are no moving parts in the device; instead, the whole unit shifts when the rope gets weighted, pinching the rope against the carabiner and impeding its movement. While you still have to keep your hand on the brake end, you don't have to hold the weight of the climber, taking the pressure off your hands and elbows. It's lightweight and fairly simple to use once you get used to it. We like the way the Smart 2.0 feeds out slack better than the ATC Pilot or the Climbing Technology ClickUp+, and since it's also cheaper, it was a no-brainer for us to give it our Best Buy award.
There is a learning curve though, and the Smart 2.0 uses a unique belaying method. The thumb of the brake hand presses up against the lever when feeding out slack. If you don't press hard enough you'll short rope your partner, but with a bit of practice, it becomes more intuitive. It also has a different lowering method; you have to pull the lever up slowly to let out slack, and the lower wasn't quite as smooth on the Smart 2.0 as the ATC Pilot, but was quite a bit smoother than we experienced with the ClickUp+. While all of these options might seem a little gimmicky at first, they do fill a much-needed niche: assisted braking at an affordable price. If your hand is tired from using tubular devices and you long for the lock-off power of an assisted braking device, but don't want to shell out the big bucks for one, the Smart 2.0, is a good compromise.
Read review: Mammut Smart 2.0
Top Pick for Multi-Pitch Climbing
Black Diamond ATC Guide
For climbers that like to do it all, our recommendation is the Black Diamond ATC Guide. This device offers the same ideal characteristics as the ATC XP for standard belays while also providing auto-block capability for bringing up followers directly on an anchor. The GriGris are only able to belay a single strand, and that limitation classifies it as a luxury in our eyes. Most climbers will also need a two strand device for rappels, and the ATC Guide is our favorite.
The Petzl Reverso put up stiff competition by offering similar features and weighing an ounce less. They both retail for around the same price, but the ATC Guide eked out the win thanks to its lower auto-block resistance. If you need a versatile option for multi-pitch climbing, look no further.
Read review: Black Diamond ATC Guide
Best GriGri Alternative that Feeds Slack Safer
As long as there have been GriGris, there have been imitation devices made by competing companies attempting to capture a bit of the market share, while also solving some of its inherent problems. While it has been a long time coming (due partially to a recall in 2017; the problem is fixed), the Trango Vergo is one of the most appealing active assisted braking devices we have tested. Its most endearing feature revolves around safety: it is not possible to lock out the catch cam mechanism, like it is on the GriGri. This feature alone greatly reduces the chances that a belayer could accidentally drop the climber while clipping, a problem even more dangerous when the climber is close to the ground. The cam that pinches the rope to provide the braking assist does not have a spring in it, but uses the angle by which the rope is running over it to determine whether there is enough friction to catch or stay open. Feed out slack to the side as recommended, a method that allows one to pay out longer loops of slack with one arm, and the cam stays open. Pull upwards, in the direction that a climber would, and the cam uses friction to automatically lock up. The ergonomic design of the Vergo also allows you to hold the brake end of the rope in the same hand as the device without bending it back, so there is less friction to overcome when pulling out slack. Once mastered, this method proves far easier, and safer, than lead belaying with a GriGri.
Of course, like all assisted belay devices, a new technique must be learned and mastered in order to be an effective belayer, especially for leading. Compared to the other active assisted braking devices, though, we found this technique to be relatively quick and intuitive to perform, and didn't require much thinking after only a pitch or two. The Vergo also doesn't have the same anti-panic handle as the GriGri+ or Camp Matik, so it is possible to open it up full bore while lowering and drop a climber very fast. The Vergo is only good to go with ropes 8.9mm and thicker, so beware if you commonly use an ultra thin cord. Lastly, while Trango makes it clear in all its instructional documentation and training videos, it is easy to accidentally clip the Vergo into the harness the wrong way, which diminishes the amount of friction a leader puts on the catch cam. We found the correct way a bit confusing since it seems to be upside down, if you are used to a GriGri's orientation, and puts a half twist into the belay loop when used correctly. Despite the minor downsides, the Vergo is far and away our favorite active assisted braking device that isn't a GriGri. We highly recommend checking it out if you don't like the way the GriGri feeds slack, or are curious about the other options out there.
Read Review: Trango Vergo
Why You Should Trust Us
This review is led by Andy Wellman, a Senior Reviewer at OutdoorGearLab since 2014. Andy has been climbing since 1996, when he learned at Paradise Rock Gym in Denver, back when Denver only had two gyms! In the intervening 23 years he has climbed pretty much full time, partaking in alpine and rock adventures from Alaska to Peru, the Alps to Asia, and all over North America. He is a former guidebook publisher and author, and has also worked as an alpine climbing guide. In order to be closer to the cliffs, he has lived in such climbing meccas as Boulder, Rifle, Chattanooga, Ouray, and now Terrebonne, Oregon, next to Smith Rock (his office), along the way easily surpassing the arbitrary mark of 10,000 hours of practice. Andy cannot fathom how many belay devices he has owned or used over the years, but estimates that he has managed to lose more GriGris than most people will ever own. Joining him on our expert panel for this review is Cam Ring, longtime climbing gear reviewer and former Yosemite Search and Rescue Member, and Jack Cramer, alpine climber and commercial fisherman. Overseeing the entire project, and also starting this continuously updated review back in 2009, is owner and editor in chief of OutdoorGearLab, Chris McNamara, long known as an expert aid climber and El Cap climbing guru.
We work hard to stay up to date on all of the latest climbing gear releases. After making a final selection of updates to this review, Andy spent over 10 hours researching the products themselves, as well as watching YouTube videos to help learn how to safely use each device, all of which require vastly different techniques! He also spoke with many climbers at the crag about their belay devices, especially the more esoteric choices, to understand what issues or advantages they have encountered that he hadn't heard of. He then belayed at least 30 pitches over the course of two months with each new model, both leading and top-roping, as well as lowering. He even fixed a rappel off the top of a cliff and spent all day rappelling laps with each different device so he could accurately compare their performance, and understand their nuances, head-to-head. Lastly, he conducted side-by-side tests in a more controlled environment to gain further knowledge.
Related: How We Tested Belay Devices
Analysis and Test Results
Gone are the days of hip belays and the adage "the leader must not fall." Along with dynamic ropes, the reliability of modern devices has transformed climbing from a borderline suicidal endeavor to a boring choice for a kid's birthday party. If you climb enough, though, you'll eventually wonder which device offers the best friction in the lightest, most affordable, and easiest to use package.
Belay devices are important pieces of climbing life-safety equipment but can be confusing to master. This is one piece of gear where learning exactly how to use it properly is crucial. Improper use of a belay device may result in death or serious injury. It is very important that you read and carefully follow the manufacturer's instructions. We encourage you to visit the manufacturer's website and make sure you have their latest documentation for your particular device, as manufacturer's recommendations sometimes change over time as new safety guidelines are developed. Climbing is dangerous. Climb at your own risk.
A new belay device can run anywhere from $20 to $200. The lower end of the range is populated by tube-style devices, whereas the more expensive models are the active assisted braking devices. The simple tube-style devices can get the job done for a fraction of the cost, so why would anyone want to spend so much more on one? Most assisted devices provide an extra level of safety should the belayer let go of the rope for various reasons (gets slammed into the wall, is knocked unconscious, or simple operator error). But often climbers require one of each - an assisted device for belaying and a "tuber" for rappels. If you're looking for the best value out there, we've picked out a few that we consider exceptional. To begin, the Black Diamond ATC XP can't be beat on price and is a solid and reliable option. Note that our Best Buy for Assisted Braking, the passive Smart 2.0, didn't have a very high score because we couldn't rate it for its auto-locking ability. However, it's a good deal. We also like the Petzl GriGri much better than the Camp Matik which is double the cost.
This category measures and rates how easy it is to catch a fall with a belay device. Of course, every belay device here will catch a fall by arresting the rope provided they are used with proper technique, but due to their unique designs, the assisted braking devices tend to do this with more reliability, and far less effort, than a standard tube-style device. For instance, to catch a fall with a tube style device, the belayer must lock the rope off by down by their hip, while also gripping tightly to the rope to keep it from slipping. With an assisted braking device, whether passive or active, the slightest amount of gripping pressure on the brake rope will provide the tension and friction required to lock up the device, holding the climber in place. Which brings up another important consideration in this category: how easy it is to hold a climber locked off. Obviously, the assisted braking devices are supreme once again, and the ability to easily hold a climber for an unlimited amount of time with little to no effort is the number one argument for using one of these devices while climbing.
The final consideration for this metric is the range of rope diameters that a belay device is capable of gripping. Ropes on the narrow side can slip through some belay devices due there not being enough friction if the design doesn't take narrow ropes into consideration. As the quality of rope manufacturing has increased, climbers are far more frequently using thinner ropes, with 8.9mm-9.2mm being much more common, and 9.5mm now being considered a reasonably fat "workhorse," where it was considered thin a mere 10 years ago. The thinnest single ropes on the market today are only 8.5mm (!), so having a belay device that can handle these thin ropes certainly adds value. On the upper end of the scale, ropes over 9.8mm, especially ones that are worn a bit so they are fuzzy, create extra friction that can make it hard to easily force then through a belay device quickly. As more and more climbers transition to thinner ropes, this is becoming slightly less of an issue, but once again, added versatility in regard to rope sizes only increases the value of a belay device.
The active assisted belay devices that employ a springed cam to pinch the rope when it is under tension provide the easiest and most reliable catch. Due to their cam, they even allow a small amount of rope (a couple inches at most) to slip through the device as they lock, which increases the dynamic aspect of a catch, reducing the forces on the climber, rope, and gear slightly. The devices that reliably catch like this are the Camp Matik, as well as the GriGri and GriGri+, and they received the highest scores. Both of the GriGris are also now capable of handling ropes down to 8.5mm.
Second best when it comes to this category are most of the "passive" assisted braking devices, like the Edelrid Mega Jul, Mammut Smart 2.0, and Black Diamond ATC Pilot. In "active" models, braking is created by a pinching mechanism inside the device itself; "passive" models rely on a pinch between the carabiner and the device to hold the rope. Passive models are thus dependent on this carabiner, and its shape and size can have a significant impact on performance (up to 35% differences in our tests). Always use these devices with the manufacturer recommended carabiner whenever possible (usually an HMS type), and expect that any deviance (along with changes in rope diameter) will affect its performance.
Passive models also do not generate the same braking force as active devices. The German Alpine Club conducted tests measuring the braking force without a hand on the rope for several models and found the Smart (older model) and Mega Jul could only handle 0.6 kN and 0.5 kN, respectively. Active assisted locking devices like the GriGri 2 and Camp Matik each withstood more than 2.0 kN. While the hype might lead you to believe that they are "locking" devices, they cannot be expected to catch even small falls without a brake hand on the rope. To say it another way, if your belayer gets knocked unconscious by rockfall, these passive assisted braking devices might not catch your fall. Passive models do offer substantial lock-off though and save your brake hand from cramping up on long top rope belays.
The standard tube-style devices, like the Black Diamond ATC models and the Petzl Verso and Reverso are what scored the lowest compared to the rest of the field. These devices require substantial strength on the brake hand when catching a fall and continued lock-off when top rope belaying or belay your second.
Catching a falling climber is only half the duty of a belay device; getting that climber safely back to the ground is the other. That's where lowering and rappelling come in. Six of the devices we tested began with an automatic advantage in this category — the ability to rappel two strands. Those models are the ATC XP, ATC Guide, Verso, Reverso, Smart Alpine, and Mega Jul. Rather than include that difference in our numerical scoring, we chose to separate it as a simple 'yes or no' double strand question in our comparison matrix. Shoppers should recognize that the none of the active assisted locking devices can rappel a doubled rope, nor can the passive ClickUp+, Black Diamond ATC Pilot, or Mammut Smart 2.0. Consider these models only for single-pitch routes or multi-pitches in combination with a two-strand device.
The difference in lowering/rappelling scores comes down to the smoothness of the action and the range it is good for. We saw the most consistently good performance from the tube devices. Although the assisted braking models all provide the ability to lock the device and rest hands-free, they also exhibit narrow ranges and jerkiness. The tube style belay devices offer the smoothest lowering and rappelling of all models reviewed.
The standout performance from assisted braking devices came from the GriGri. The lower on that unit is smooth and jerk free, largely due to the absence of an anti-panic mechanism. The GriGri+, Camp Matik and Edelrid Eddy all have anti-panic levers that operate in a similar manner. If you pull back too far on the lever, the unit locks up. While this is to prevent someone from accidentally dropping themselves or their partner, it creates a narrow window between lowering and locking up. The Matik and Eddy locked up on us more than the GriGri+, but all require a deft hand that does improve with practice. These devices are unquestionably safer for lowering partners, but can also be perceived as more annoying to use.
The passive assisted devices have some of the poorest lowering action. We often find them jerky when compared to the tube devices. However, because you need to push and pull on them quite a bit to lower your partner, they are quite safe to use and lock up as soon as you let go.
Feeding slack is a category we include to measure each device's usefulness for belaying a lead climber. A lead climbing belay requires more attentiveness and rope management skill than a top-rope belay. The ability to take and give slack quickly and precisely is important to ensure a good belay — especially when close to the ground. The most important thing to consider when assessing for this metric is how easily and safely can I feed slack without the device locking up? Devices that lock up on a hair trigger are very difficult to master, and are the cause of many frustrated lead climbers as they are continuously short-roped by their belayer. A secondary consideration, since we are all guilty of making mistakes, is how easy is the device to release once locked up so that I can quickly begin feeding slack again? When a climber is yanking for rope, desperate to make a clip before falling, and the device locks up, being able to quickly release it can make a difference between success or a nasty extra long fall.
Tube devices require the simplest motion to take or feed slack and receive the best scores in this category because of it. They are also the easiest to learn how to use, and are most climber's introduction into belaying. The Black Diamond ATC XP and Guide units and the Petzl Verso and Reverso all have the smoothest and easiest action.
When it comes to the passive and active assisted braking devices, results were more mixed. For the passive devices we like the Edelrid Mega Jul and the Mammut Smart 2.0 the best. These units use similar movements to tubes but require upward pressure on a handle or loop to disable the device's locking mechanism when feeding out slack quickly. The Smart 2.0 needs only a little upwards pressure to prevent it from locking, whereas the Black Diamond ATC Pilot requires substantial and continuous pressure. The Climbing Technology ClickUp+ requires using a tube-style method of feeding out slack, but is very quick to lock up, and somewhat difficult to unlock quickly compared to others.
The active assisted braking devices have some of the more complex methods for giving slack quickly, and each features a different method. The new Trango Vergo has the most ergonomic and smooth feeding design of any of these devices, and does not require overriding the camming system to feed out slack, a nice safety feature. The Petzl GriGri and + feed slack well with little friction, but often require a technique that can reduce the safety of the device, especially if the climber is close to the ground. The Edelrid Eddy and Mad Rock Lifeguard have more friction which makes it challenging to pay rope out quickly. The Camp Matik uses a unique "pistol" grip design which does take some getting used to if you've belayed differently for years.
Even if you think you are belaying correctly, chances are pretty good you may be doing something wrong! A climbing gym study in Germany showed that a quarter of all GriGri users pay out slack improperly, momentarily taking their brake hand off the rope (we've said it before, but it bears repeating, never take your braking hand off the rope!). When it comes to tube-style devices, each user committed at least one error when using them, either keeping their brake hand too close to the tube or not keeping the brake end down low enough. Therefore, no matter which device you choose, find out how to use it correctly. And that's especially true for the more complicated techniques required on active assisted braking models.
Like all climbing gear these days, belay devices are getting lighter and smaller. Weights range from 2.0 to 13.0 ounces. Whether the weight is a critical component for you depends on a few things: whether or not you are climbing with your device on your harness, and whether or not you appreciate the "training" weight in your backpack.
When it comes to something you'll likely carry on your harness, the Edelrid MegaJul, Petzl Verso and Reverso, and the Black Diamond ATC XP are the lightest options. The ATC Guide adds another ounce to your harness but not much more bulk, whereas the Mammut Smart Alpine is both a little bulkier and heavier still. Among the active assist braking devices, the Mad Rock Lifeguard is a nice alternative for those that like to multi-pitch climb with a GriGri. It's only a little bit lighter but a lot more compact.
Auto Block (Resistance Belaying a Second)
Belaying a second directly off the anchor is a convenient way to ensure a reliable catch and a comfortable belay during multi-pitch climbing (be sure to read the manufacturer's instructions carefully, as this type of belay configuration is more complex and mistakes can result in death). All the devices we tried, except the Black Diamond ATC XP and Pilot, Mammut Smart 2.0, and the Petzl Verso, feature some way to do so. Unfortunately, though, many of these devices create substantial friction that can exhaust a belayer's shoulders and elbows, and in extreme usage, like for mountain guides, can lead to tendonitis.
Our grading for this metric took into consideration whether a device is capable of being used this way or not, and whether it is easy to set up or very confusing and difficult. Secondly, we assess for versatility, scoring models that can accommodate two ropes a bit higher. Lastly, we took into consideration the amount of friction in the system, which effects the amount of energy it takes to belay in this manner, with the smoother devices being preferred.
To assess for friction, we took inspiration from Blake Herrington at Cascade Climbers to run a test on the resistance of each device in auto-block mode. The important thing to know is that the actual numerical value (in lbs.) is not very meaningful. Rather, focus on the relative performance of each device compared to the others. Lower scores are better and indicate less energy required for auto-block belays. The 1-10 scores we awarded for this category assume each device is capable of properly locking and only reflect the relative resistance. Both GriGri models scored top marks in this metric, while the Mammut Smart Alpine very disappointingly fell to the bottom.
Purchasing a belay device can be confusing with the more evolved and specialized options on the market today. Hopefully, we have helped you narrow done the options and set you on the "route" to finding the perfect one for your needs. Once you have selected your next model, please take the time to educate yourself fully on how it operates and employ the standard safety checks routinely to ensure that climbing remains a fun pastime and not some less pleasant alternative.
— Andy Wellman, Cam McKenzie Ring, Steven Tata, & Jack Cramer