Screw gates have been the locking carabiner standard since their inception in the late 1890’s. Auto-lockers entered the climbing scene in the 1970’s but due to their increased weight and somewhat complex operation they have primarily been used by more safety-conscious climbers.

Fortunately, auto-locking carabiner design has seen unprecedented change in the last few years. New designs have made them lighter, cheaper, easier to use, and much more accessible to all climbers.

For more details watch the video below to see a comparison of how to open a screw gate carabiner versus a standard auto-locking carabiner.

What is an “Auto-Locking” Carabiner

A carabiner that ensures safety by locking itself shut after it’s been opened.

Until recently auto-locking carabiners have required a series of debatably frustrating twists and pulls to open the gate, and when you release the gate it automatically closes and locks. The actions required to create the safety benefit are the same actions that make these “twist lock” carabiners more challenging to use.

The standard twist lock (most auto-locking carabiners)

The more traditional twist lock design consists of two main types:

  1. The standard twist lock (the auto-locking carabiner in the video above) requires 2-operations (2-stage) and opens with a twist followed by pressure on the gate. Other common names include 2AL, quicklock, Triact-Lock, and 2Lock.
  2. The other, more complicated, twist lock type is a 3-operation (3-stage) locker, requiring a pull, a twist, and then pressure on the gate to open. These are also referred to as triple lock, 3Lock, Locksafe, or Auto 3.
Traditional Auto Locking Carabiner Opening
the series to open a 3-stage auto-locking carabiner

Climbing gyms that provide pre-rigged GriGri’s (a belay device with assisted braking) will often come equipped with a 3-stage auto-locking carabiner, with the intention of adding as much safety as possible into the system.

Unique auto-locking carabiners

Ok, so we’ve heard the complaints of normal auto-locking carabiners: too cumbersome to use, and too heavy. But today, there are auto-lockers that are faster, safer, and lighter than the equivalent screw gate carabiner.

But there is a slight catch: With these new designs it’s more important than ever to make sure your hand can operate the release mechanism easily (think: getting it off your harness while pumped). Some of the new auto-locking carabiners will take some practice to use one-handed, but it’s totally worth the few minutes of feeling like Edward Banana Hands. Final caveat: since they required a substantial amount of R&D to develop, they come with a higher pricetag than their screw-gate counterparts.

Black Diamond

A 2012 debut, the Magnetron series is an auto-locking carabiner that uses magnets instead of a rotating sleeve to lock the gate. Buttons on opposite sides of the carabiner gate are squeezed at the same time to release the magnets and open the gate. Particularly small handed folks will need practice in grabbing the carabiner in an appropriate orientation to be able to reach the lock.  The mechanism is fast and easy(ish) to operate in most situations but it does require using a thumb and finger on either side of the gate. The Magnetron series is slightly heavier and significantly more expensive than their screw gate counterparts.

Magnetron VaporLock Magnetron GridLock Magnetron RockLock
BlackDiamond_MagnetronVaporlock_carabiner_0 BlackDiamond_Magnatron_Gridlock Blackdiamond_Magnetronrocklock

VaporLock Details


GridLock Details


RockLock Details



The intuitive Slider series of auto-lockers uses a button on the front of the gate that you press slightly and pull down. Some climbers have called the lock mechanism flimsy (perhaps because there is a small amount of side to side play in the button?), but WeighMyRack testers have been very impressed with how easy the mechanism is to use while climbing and found it easy to open with different hand positions and sizes. The Edelrid Slider series are currently favored by WeighMyRack testers for their ease of use, speed and light weight.

Pure Slider HMS Strike Slider HMS Strike Safelock HMS Strike Slider FG
Edelrid_Pure_Slider-Locking-Carabiner Edelrid_HMS_Strike_Slider Edelird_HMS_Strike_Safelock Edelrid_HMS_Strike_Slider_FG
Pure Details Strike Details Safelock Details  

Slider FG Details



2015 marks the U.S. debut of Grivel’s dual-gate auto-locking carabiners. These ‘biners take some time and humility to get used to; with practice they can become easy to use and faster than any screw gate. Once mastered, these twin gate ‘biners can be used just about anywhere a standard carabiner is used. Expect these auto-lockers to appear in each of the Grivel carabiner body shapes and in wire/wire, wire/solid, and solid/solid gate configurations in the future. Aside: We noticed combinations that include a wire gate are easier to use.

Sigma K8G Lambda K7G Mega K6G Plume K3G
Grivel Sigma K8G Grivel Lambda K7G Grivel Mega K6G Grivel Plume_K3G

Sigma Details

Lambda Details  

Mega Details

Plume Details



The Ergo Wire is an interesting product. It was designed more for adventure parks and via ferrata as the upper lever that locks the gate when it is loaded also prevents wear on the carabiner frame – particularly helpful when the basket of the ‘biner is running on steel cables.

Small handed folks will the find the ergonomics are particularly nice. Take note: This is another carabiner that can take some practice to master one-handed operation.

Ergo Wire
Kong Ergo Wire
Ergo Wire Details



A 2015 debut, the Crag HMS Slidelock is a take on the button concept. Each side of the gate has a button that needs to be depressed then pulled down for the gate to open. Like the Magnetron, the Crag HMS Slidelock uses a pinching action but then also a slight pulling action to slide the mechanism down the side of the gate. This requires the carabiner to be held fairly low which may take some time to get used to. This is also quite a large HMS so small hands will need to practice some stretching techniques.

Crag HMS Slidelock
Mammut hms crag slidelock
Slidelock Details



One of the earliest designs to try something beyond the pull-and-twist design, was the Ball Lock. Once the button is activated the user still needs to twist the sleeve to open the gate. The twist is necessary to prevent accidental openings because the ball sits proud on the gate, compared to recessed buttons found on more recent designs such as the Magnetron and SlideLock.

Update: These Petzl carabiners are no longer produced. You may be able to find some, but they are not readily available anymore.

AM’D Ball Lock William Ball Lock
Petzl_AM'D_Balllock Petzl_WilliamBalllock

AM’D Details


William Details

So, how many do you need, if any?

Auto-lockers can be used anywhere a locking ‘biner is desired: belay/rappel carabiner, personal anchor, power point, top rope anchors, or mid-rope connection for glacier travel.

Unsurprisingly, auto-lockers are often given/recommended to new climbers or guided climbers as they feel safer and it’s impossible to forget to lock it.

The number of auto-lockers to use has been up for debate since their inception. In short: use them interchangeably for any situation where you would have used a locking screw gate carabiner. Otherwise, here’s a guide for how other climbers use auto-lockers:

Zero: Each climber will have their own objections to them. Here are a few: too cumbersome, too heavy, too expensive, or impossible to open one-handed. However, many climbers may be unaware that most of these justifications are quickly becoming obsolete with new designs.

One: Auto-lockers are most commonly used as a belay carabiner, increasing the speed and safety at the point of most frequent use of a locker.

Two: Belay carabiner and one for a personal anchor.

Three: Belay carabiner, two as a top rope anchor. Or belay, personal anchor, and belaying a following climber in guide mode. Or belay, anchor power point, and personal anchor.

With the increased speed and ease of use we’ve seen auto-lockers used in critical clip scenarios such as sketchy first draws and long traverses where a fall would be detrimental.

Four +: Use ’em anywhere and everywhere you’d like a locker. Some climbers will never use 4 lockers on a climb, but there is no rule against it. Safety conscious climbers that want more redundancy in the system can always find uses for another locker.

Compare every auto-locker made today at:

Any downsides to auto-locking carabiners?

  • If you have smaller hands and the carabiner is large they can be frustrating to use.
  • One-handed operation will vary depending on the locking mechanism.
  • Although there are affordable auto-lockers (prices start at $11.95), generally screw gates are cheaper (starting at $7.50).
  • Although there are light auto-lockers (the weight starts at 42 grams), generally screw gates are lighter (starting at 37 grams).
  • It can be difficult to quickly identify it is actually locked without pressing on the gate.
  • You may get in the habit of using auto-lockers and forget to lock/check your manual screw gate lockers.
  • Technically, there are fewer options, but 100+ models is still plentiful!

Remind me of the upsides again

It’s all about safety. And time. And mental assurance.

There are auto-lockers available now that are reasonably priced, easier and faster to use than the screw gate alternative. So it’s possible to eliminate all the downsides stated above.

Unfortunately, I cannot provide the exact model name that fit the needs of every scenario, as this will differ for each climber. If you’d like to know my personal preference, I am a huge fan of Edelrid’s Slider carabiners. I use the Strike Slider HMS as my belay ‘biner and the Pure Slider (tied for 3rd lightest locker) as my personal anchor ‘biner. I was given these carabiners to test and I like them so much I don’t even share them with my life/climbing partner – hands off, buddy.

How to choose the best auto-locking carabiner

There are now over 100 auto-locking carabiners available which seems like a lot, until you start narrowing it down to your key criteria.

Criteria (other than ergonomic fit, which we believe is essential for all gear buys):

  • The amount of work involved to open (2-stage is easier to use, 3-stage is even less likely to open inadvertently)
  • Price (do you have a max budget?)
  • Shape (read this post if you need help picking between Oval, D, offset D, and Pear/HMS)
  • Size (as is true with screw-gates, auto-lockers come in most sizes from small offset D to gigantic HMS)
  • Weight (is weight a critical factor given the type of climbing you’re doing?)

Bottom Line

If increasing safety and saving time aren’t big enough reasons to jump on the auto-locking bandwagon then stick with screw gates. In our opinion, the only reasons to not investigate the latest auto-lock options would be if they didn’t fit your hands, they didn’t come in your preferred carabiner shape, or they were out of your price range.

I expect auto-lockers will only increase in ease of use as they convert to the new standard in safe climbing. And once the market increases we’ll find more price reductions as well.

If you’re convinced, here are the spots you can find the most recent innovative offerings:

Alison Dennis

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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