Arkose MatchKey challenges have revolutionized CAPTCHAs

Traditional CAPTCHAs don’t work because bots get around them. But Arkose MatchKey challenges are designed to meet modern threats head-on by providing the best of defensibility, usability, and accessibility in one product. In fact, Arkose MatchKey is the strongest CAPTCHA ever made. 

Arkose MatchKey Challenges

Arkose MatchKey is a state-of-the-art series of challenges with industry-leading security.

  • An unparalleled variety of 3D imagery.
  • Our strongest challenges may produce more than 1,250 variations of a problem to solve. All are incredibly easy for legitimate users, but the variety makes it incredibly difficult to solve with automation.
  • We use a key image to solve the largest problem with challenge design: Conveying instructions that are universally understandable across all languages and cultures.
  • Large, aesthetically pleasing images are easy to see. No more zooming-in, trying to find traffic lights in blurry photos.

Arkose MatchKey Challenges

Arkose MatchKey Challenges Try the Challenge

Variable Difficulty

The more variables the attacker must take into account, the more difficult it is to automate.

Variable Difficulty

Enhanced Audio Challenges

We have the industry’s largest variety of audio challenges.

  • Instead of type what you hear (or alphanumerics) puzzles, we ask users simple questions using delightful and amusing scenarios
  • 20+ new audio challenges
  • Industry-leading completion rates for accessibility options

Enhanced Audio Challenges

Hear the audio challenge

Which option is drums?

Which option is the fake bee sound?

Which option has only one person speaking?

Click Play to hear the audio

How We Test Challenges

Automation Testing

Automation Testing


Variations of a question to look for per challenge.


Labeled images required to build a ML solver


Hours of human labor to label images

We test our challenges against state-of-the-art machine learning.

  • By iterating against machine learning, we know exactly what it would take for an attacker to automate a challenge.
  • Our strongest challenges could result in a half-million individual images that an attacker would have to hand-label for a machine learning algorithm.
User Testing

User Testing

Every Arkose MatchKey challenge is tested on humans. We release challenges only when they meet very strict usability benchmarks. Our strongest puzzles, designed for bad actors, have no impact on good user completion-rates.

Our interfaces have full A11y Accreditation, and are keyboard and alt-device (touchpads, trackballs) compatible.



Our challenges look and feel native because we can style the front end to match the branding of your website or app.


Why Not Just Use a Traditional CAPTCHA?

  • The most easily identified photos are already labeled by off-the-shelf machine learning-based solvers.
  • Users have a bad association with difficult photo CAPTCHAs.
  • Image recognition software continually improves image-detection at the cost of reducing defensibility and usability of traditional CAPTCHAs.

Stop Bots, Not Customers with Arkose Labs