How to Solve CAPTCHA Image Detecting Issues

July 25, 2023

How to Solve CAPTCHA Image Detecting Issues

Research done by Dan Cesa

The Internet has countless users, but you know what? Many of them are actually bots. So, what’s the solution to filter out these bots? Well, it’s none other than the use of a CAPTCHA image.

In 2019, a significant discovery was made regarding the presence of Twitter social bots during the 2019 Spanish general election data. Automated accounts played a significant role in shaping public opinion and discourse during the election. The findings shed light on their impact, emphasizing the need to address the influence of social bots in our digital age.

What CAPTCHA requires is for someone to correctly evaluate a sequence of letters or numbers in a distorted image displayed on the screen. Nowadays, people use automated CAPTCHA solving service for various reasons. Some of these uses are illegal, while others serve legitimate purposes.

What is a CAPTCHA?

CAPTCHA is no longer a foreign concept to web users. It’s that annoying human validation check that pops up on countless websites. But what exactly is CAPTCHA? It’s an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”. In simple terms, CAPTCHA is like a bouncer for the internet, keeping out bots and automated scripts that try to wreak havoc.

The idea behind image recognition services or CAPTCHA is that only humans can pass this test, while bots are left scratching their nonexistent heads. It’s a clever way to ensure that online users are real humans, not sneaky machines trying to cause trouble.

What are CAPTCHA Images Used for?

Ever wondered why we encounter those CAPTCHA images? Well, they are not just random complex tests! CAPTCHAs employ clever techniques to differentiate between humans and bots. Imagine running an online business where you want your customers to leave product reviews in the comments section.

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But here’s the catch—you want to ensure that those entries are genuinely from your customers or, better yet, from actual human visitors to your website.

To elaborate on the idea, here are some of the common use cases of CAPTCHAs:

Preventing spam

By incorporating CAPTCHAs into their systems, website owners and email service providers can effectively deter spam bots and maintain the security and integrity of their platforms. CAPTCHAs are designed to verify users are human and not computer programs by presenting such tests that are easy for humans to solve but difficult for bots.

Enhancing account creation security

CAPTCHAs have a vital role in the battle against fake accounts by identifying between human users and automated bots. This added layer of security helps to maintain the trust and authenticity of user interactions on websites.

Safeguard against data scraping

Preventing data scraping is crucial for safeguarding sensitive information. By requiring users to complete specific tasks or solve puzzles, CAPTCHAs verify that the user is a human and not an automated script attempting to scrape valuable data.

Protecting against bot-driven attacks

Bots are often used to launch malicious website attacks, such as denial-of-service attacks. CAPTCHAs can help protect a website against such attempts by preventing bots from accessing restricted areas or performing certain actions. It safeguards the integrity of web pages and other sensitive information.

Advantages of Using CAPTCHA

Whether you’re a website owner or an email service provider, there are multiple advantages to using modern CAPTCHAs on your platform.

Here are some of the benefits of deploying CAPTCHA technology:

Affordable protection

Most CAPTCHAs are free, and those that do require a fee are quite affordable. This means that any website or online service can incorporate this layer of protection without having to break the bank.

woman working on laptop and phone

Easy to integrate

CAPTCHA solver integration is fairly straightforward and can be done with a few lines of code. Most CAPTCHAs don’t require any additional hardware or software, which makes them even more cost-effective.

Improved user experience

Modern CAPTCHA technology uses natural language processing (NLP) and Artificial Intelligence (AI) algorithms to provide a better user experience without compromising on security. Not only are CAPTCHAs secure, but they also make sure that users don’t get frustrated by providing easy-to-use puzzles or tasks.

Disadvantages of Using CAPTCHA

While the advantages of CAPTCHAs are undeniably impressive, it’s important to acknowledge the significant drawbacks that cannot be ignored.

Let’s dive into the key disadvantages of CAPTCHA:

Not suitable for visually impaired users

Image-based captchas are typically very hard for visually impaired people to identify. Even if audio CAPTCHAs are available, the distorted sound of words can still be difficult to understand and interpret.

Requires both time and effort to complete

For many users, taking the time to decipher an image or solve CAPTCHAs with puzzles can be incredibly tedious. This may lead some visitors to abandon their purchase altogether, costing the website in terms of lost revenue.

Prone to failure

No system is flawless, and CAPTCHAs are certainly no exception. But let’s face it, CAPTCHAs may be great at combating spam, but they’re not foolproof. Their applications, well, let’s just say they have their limitations and flaws.

person using a macbook

Solutions for Your CAPTCHA Test Issues

Errors in traditional CAPTCHAs tend to occur often due to their dependence on image recognition algorithms. If you’re having trouble with CAPTCHAs, it may be time to look into alternative options.

Here are the popular CAPTCHA-solving methods available for users to solve the CAPTCHA:

1. Online CAPTCHA-solving services

With a team of dedicated human workers available round the clock, these services offer to crack those challenging CAPTCHAs. Simply send in your request, and their human workers can swiftly break through the puzzles, returning the solutions to you in no time.

2captcha is a big and popular CAPTCHA solver that provides services for various websites and APIs.

2. Machine learning (Image recognition)

Machine learning and image recognition can come to the rescue. With computer vision, convolutional neural networks, and Python frameworks like Keras and TensorFlow, ML can train models to spot those random letters and digits in the CAPTCHA image.

There are many ways to achieve this; below are samples:

Python libraries:

  • OpenCV – to solve the CAPTCHA through Object Detection
  • Pillow – An image processing library in Python.

Process Flow:

  1. Convert image to greyscale 
  2. From the greyscale image, locate the icons
  3. Then rotate the detected icons until it match the target icon
attempt to solve geetest captcha
  • ImageAI – built to empower developers, researchers, and students to build applications and systems with self-contained Deep Learning and Computer Vision capabilities using simple and few lines of code. 

Process Flow:

  1. Collect/Gather lots of images
  2. Annotate objects on each image collected
  3. Train YOLO Model based on collected annotated images
  4. Apply trained YOLO model to detect target objects in the image

3. Consider outsourcing CAPTCHA solutions

In today’s world of technology, outsourcing has become the go-to solution for many businesses. It’s an effective way of leveraging external resources to get work done quickly and cost-effectively. CAPTCHA solving is no exception here!

If you don’t want to handle CAPTCHAs yourself, there are a number of reliable companies that provide this service at a reasonable price.

Which is the Best Tool?

In conclusion, 2captcha, OpenCV, and ImageAI are all valuable tools in image processing and captcha solving.

Categories2captchaOpenCV + PillowImageAI
Cost$5/1000 captcha solveFree(Open Source)Free(Open Source)
DocumentationGood documentationWell documentedNeed improvement in other areas
SupportExcellent support with the ticketing systemWide range of comprehensive communityLess support
Data collectionThere is no need to handle the image processing; simply send the image to the API, and they will solve the captcha.Almost zero effort since we can get the object directly from the imageNeed a lot of images and annotating each object in the image to train the YOLO model
Object detection speedThe API response is less than 30 seconds.Depends on the complexity of the image pixelsOnce the trained YOLO model is done, it almost instantly detects objects in the image
Implementation timeThe implementation of the API makes it faster than other methodsCalculating the best threshold for each image takes a lot of timeIt will be based on the data collection. And fewer codes to implement
Object detection accuracyBecause of human interaction, captcha solving has an accuracy of 99%Because of human interaction captcha solving has an accuracy of 99%Because of human interaction, captcha solving has an accuracy of 99%

2captcha provides an API-based solution that offloads the captcha-solving process to their system, allowing for convenient and efficient captcha resolution.

On the other hand, OpenCV is a powerful open-source computer vision library offering a wide range of image processing capabilities. It provides developers with a comprehensive set of functions and algorithms to handle various image manipulation, analysis, and recognition tasks.

ImageAI is a user-friendly Python library that utilizes pre-trained models to perform various computer vision tasks, including object detection, image recognition, and image classification. It simplifies implementing complex image processing functionalities, making it accessible to developers with varying levels of expertise.

While 2captcha focuses on solving the CAPTCHA, OpenCV and ImageAI provide broader image processing capabilities. Depending on the specific requirements and use cases, developers can choose the most suitable tool or combine them to achieve their desired results.

Overall, these tools significantly contribute to the advancement of image processing and automation, enabling developers to easily build robust applications that involve image manipulation, analysis, and recognition tasks.


Image recognition technology has become an essential tool for many industries and businesses. It offers a wide range of benefits to our organizations and API clients. By leveraging this technology, our organizations can streamline processes, increase efficiency, and enhance customer experiences.

If you want to implement a CAPTCHA image on your website or app, it is important to have the right security measures in place!

StarTechUP Solutions for Your CAPTCHA Vulnerable Issues

Here, at StarTechUP, we understand the importance of having the latest security measures in place. Our team of experienced security experts is well-versed in tackling CAPTCHA-related issues and can help you identify, analyze, and resolve any CAPTCHA vulnerabilities on your websites or apps.

The features listed are based on what I think is relevant to our organization. Here are the features we can offer as a product development company business:

  • Image background removal – Background removal of images is a feature that can be utilized in various applications such as e-commerce product uploads and avatar profile pictures. It is particularly useful for clients who desire to quickly upload their products without spending a lot of time editing or removing background images.
  • Background change  – Improve product presentation in e-commerce, personalized avatar, etc. Aside from background removal, we can make e-commerce product pictures more visually appealing and engaging to the customer.
  • Watermark –  Add a watermark on images to protect copyright. More and more organizations are investing in high-resolution images and videos for their products or services. With our watermark feature, they can protect their assets from malicious users who intend to steal content.
  • Document scanner – Offering document scanning features to clients can provide a range of benefits that can help to improve customer experience, increase efficiency, save costs, and provide a competitive advantage.
  • Text-to-image -Text-to-image technology can create eye-catching graphics and promotional material, helping attract and retain customers. And to create branded graphics, businesses can ensure that their visual content is consistent and aligned with their brand guidelines.
  • Face recognition  – Image recognition technology can be used for security purposes such as facial recognition, object detection, and surveillance.

In-House benefits:

We can also take advantage of the benefits we can gain from image recognition by using the features below:

  • Dominant colors – Sometimes, clients only provide a logo or image without specifying their preferred colors. In such situations, the detection of dominant colors can assist our UI/UX developers in determining which colors to use for that particular project.
  • Document scanner – is an important tool for anyone who wants to improve efficiency, reduce physical storage space, and protect important documents. For example, if our operations manager has an urgent document that needs to be scanned, he can use his mobile device to scan it directly rather than going to the office.
  • Text-to-image -Converting text to images can be quicker than creating custom graphics from scratch, allowing us to create more content in less time.

At StarTechUP, we are ready to help! We also offer mobile app development, web development, and other related services. Our experienced team of developers can provide the best solutions to help your business succeed.

Contact us today to learn more!

About the author: Andrea Jacinto - Content Writer

A content writer with a strong SEO background, Andrea has been working with digital marketers from different fields to create optimized articles which are informative, digestible, and fun to read. Now, she's writing for StarTechUP to deliver the latest developments in tech to readers around the world. View on Linkedin