{"id":9892,"date":"2026-06-07T19:37:23","date_gmt":"2026-06-07T17:37:23","guid":{"rendered":"https:\/\/mybox.com\/help\/?post_type=manual_kb&#038;p=9892"},"modified":"2026-06-07T19:37:24","modified_gmt":"2026-06-07T17:37:24","slug":"what-is-captcha","status":"publish","type":"manual_kb","link":"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/","title":{"rendered":"What Is CAPTCHA?"},"content":{"rendered":"\n<div class=\"translation-block translation-block-merged\">\n<p class=\"wp-block-paragraph\">CAPTCHA is a security mechanism used on websites to distinguish between real human users and automated software (bots). It helps protect websites, forms, and online services from spam, abuse, and malicious automated activity.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The name CAPTCHA stands for:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Completely Automated Public Turing test to tell Computers and Humans Apart<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#How_CAPTCHA_Works\" >How CAPTCHA Works<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Common_CAPTCHA_Methods\" >Common CAPTCHA Methods<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Text-Based_CAPTCHA\" >Text-Based CAPTCHA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Image_Selection_CAPTCHA\" >Image Selection CAPTCHA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Checkbox_CAPTCHA\" >Checkbox CAPTCHA<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Behavioral_CAPTCHA\" >Behavioral CAPTCHA<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#What_Is_reCAPTCHA\" >What Is reCAPTCHA?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Why_CAPTCHA_Is_Used\" >Why CAPTCHA Is Used<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Spam\" >Spam<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Fake_Account_Creation\" >Fake Account Creation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Brute_Force_Attacks\" >Brute Force Attacks<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Resource_Abuse\" >Resource Abuse<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Automated_Scraping\" >Automated Scraping<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Common_Places_Where_CAPTCHA_Appears\" >Common Places Where CAPTCHA Appears<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Advantages\" >Advantages<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Limitations\" >Limitations<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/mybox.com\/help\/en\/knowledgebase\/what-is-captcha\/#Summary\" >Summary<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_CAPTCHA_Works\"><\/span>How CAPTCHA Works<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<\/div>\n\n<div id=\"mybox-2675188749\" class=\"mybox-content mybox-entity-placement\"><div class=\"early-access-banner-inpost\">\r\n  <div class=\"banner-left-inpost\">\r\n    <div class=\"icon-box-inpost\">\r\n      <img decoding=\"async\" src=\"https:\/\/mybox.com\/help\/wp-content\/uploads\/2026\/02\/square-info-icon.svg\" alt=\"Info\">\r\n    <\/div>\r\n    <div class=\"text-box-inpost\">\r\n      <span class=\"label-inpost\"><span class=\"translation-block translation-block-banner-text\">Early access<\/span><\/span>\r\n      <h4><span class=\"translation-block translation-block-banner-text\">Still need help?<\/span><\/h4>\r\n      <p><span class=\"translation-block translation-block-banner-text\">Contact our customer service team.<\/span><\/p>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <div class=\"banner-right-inpost\">\r\n    <a href=\"https:\/\/panel.mybox.com\/helpdesk2\/v\/list\/\" class=\"banner-button-inpost\"><span class=\"translation-block translation-block-banner-text\">Message us<\/span><\/a>\r\n  <\/div>\r\n<\/div><\/div>\n\n<div class=\"translation-block translation-block-merged\"><p class=\"wp-block-paragraph\">A CAPTCHA system presents a simple challenge that should be easy for a human to complete but difficult for automated software.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Traditionally, CAPTCHA verification required users to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Read distorted text displayed in an image.<\/li>\n\n\n\n<li>Enter the displayed characters into a form field.<\/li>\n\n\n\n<li>Complete a simple task before submitting a form.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If the test is completed correctly, the website assumes that a human is interacting with the page and allows the action to proceed.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Common_CAPTCHA_Methods\"><\/span>Common CAPTCHA Methods<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Over the years, CAPTCHA technology has evolved to improve both security and usability.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Text-Based_CAPTCHA\"><\/span>Text-Based CAPTCHA<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The user must identify and type distorted letters or numbers displayed in an image.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Example:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>X7P9K\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Image_Selection_CAPTCHA\"><\/span>Image Selection CAPTCHA<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Users are asked to identify specific objects in a collection of images.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Examples:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Select all traffic lights.<\/li>\n\n\n\n<li>Select all bicycles.<\/li>\n\n\n\n<li>Select all crosswalks.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Checkbox_CAPTCHA\"><\/span>Checkbox CAPTCHA<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A simple checkbox such as:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>I'm not a robot\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">may be sufficient when user behavior appears legitimate.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Behavioral_CAPTCHA\"><\/span>Behavioral CAPTCHA<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Modern systems analyze:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Mouse movements<\/li>\n\n\n\n<li>Typing patterns<\/li>\n\n\n\n<li>Browsing behavior<\/li>\n\n\n\n<li>Time spent on a page<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">to determine whether the visitor is likely a human.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"What_Is_reCAPTCHA\"><\/span>What Is reCAPTCHA?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">reCAPTCHA is a CAPTCHA system developed by Google.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It combines traditional bot protection with advanced behavioral analysis.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Earlier versions of reCAPTCHA often required users to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Type words from scanned documents.<\/li>\n\n\n\n<li>Identify objects in images.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Modern versions such as reCAPTCHA v3 often work silently in the background and evaluate user activity without requiring interaction.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Why_CAPTCHA_Is_Used\"><\/span>Why CAPTCHA Is Used<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CAPTCHA is commonly used to protect websites against:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Spam\"><\/span>Spam<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Preventing automated spam submissions through:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Contact forms<\/li>\n\n\n\n<li>Blog comments<\/li>\n\n\n\n<li>Support forms<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Fake_Account_Creation\"><\/span>Fake Account Creation<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Reducing the automated creation of large numbers of user accounts.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Brute_Force_Attacks\"><\/span>Brute Force Attacks<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Limiting automated login attempts against user accounts.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Resource_Abuse\"><\/span>Resource Abuse<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Preventing bots from generating excessive requests that could impact website performance.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Automated_Scraping\"><\/span>Automated Scraping<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Reducing unwanted collection of website data by automated tools.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Common_Places_Where_CAPTCHA_Appears\"><\/span>Common Places Where CAPTCHA Appears<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">You may encounter CAPTCHA when:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Submitting a contact form<\/li>\n\n\n\n<li>Registering a new account<\/li>\n\n\n\n<li>Logging in to a website<\/li>\n\n\n\n<li>Posting comments on blogs<\/li>\n\n\n\n<li>Participating in online polls<\/li>\n\n\n\n<li>Recovering account passwords<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Search engines may also display CAPTCHA challenges if they detect unusual traffic patterns or suspect automated activity.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Advantages\"><\/span>Advantages<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CAPTCHA provides several benefits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reduces spam submissions<\/li>\n\n\n\n<li>Protects user accounts<\/li>\n\n\n\n<li>Limits automated abuse<\/li>\n\n\n\n<li>Helps maintain website performance<\/li>\n\n\n\n<li>Improves overall website security<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Limitations\"><\/span>Limitations<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Although CAPTCHA is effective, it is not perfect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Potential drawbacks include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Reduced user convenience<\/li>\n\n\n\n<li>Accessibility challenges for some users<\/li>\n\n\n\n<li>Occasional false positives<\/li>\n\n\n\n<li>Advanced bots can sometimes bypass older CAPTCHA implementations<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, modern CAPTCHA systems increasingly rely on behavioral analysis and machine learning rather than traditional text recognition alone.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Summary\"><\/span>Summary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">CAPTCHA is a security mechanism designed to verify that actions performed on a website originate from a human rather than an automated bot.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is commonly used to:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Prevent spam<\/li>\n\n\n\n<li>Stop automated account creation<\/li>\n\n\n\n<li>Protect login forms<\/li>\n\n\n\n<li>Reduce malicious traffic<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Modern solutions such as reCAPTCHA combine user interaction, behavioral analysis, and machine learning to provide stronger protection while minimizing inconvenience for legitimate visitors.<\/p>\n<\/div>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"template":"","format":"standard","manualknowledgebasecat":[25],"manual_kb_tag":[4589,4590,4591,4592,4593,3108,4195,4197,4587,4588],"class_list":["post-9892","manual_kb","type-manual_kb","status-publish","format-standard","hentry","manualknowledgebasecat-hosting","manual_kb_tag-bot-detection","manual_kb_tag-behavioral-analysis","manual_kb_tag-image-recognition","manual_kb_tag-text-based-captcha","manual_kb_tag-checkbox-captcha","manual_kb_tag-spam-prevention","manual_kb_tag-bot-protection","manual_kb_tag-captcha","manual_kb_tag-recaptcha","manual_kb_tag-human-verification"],"_links":{"self":[{"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manual_kb\/9892","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manual_kb"}],"about":[{"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/types\/manual_kb"}],"author":[{"embeddable":true,"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/users\/1"}],"version-history":[{"count":1,"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manual_kb\/9892\/revisions"}],"predecessor-version":[{"id":9893,"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manual_kb\/9892\/revisions\/9893"}],"wp:attachment":[{"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/media?parent=9892"}],"wp:term":[{"taxonomy":"manualknowledgebasecat","embeddable":true,"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manualknowledgebasecat?post=9892"},{"taxonomy":"manual_kb_tag","embeddable":true,"href":"https:\/\/mybox.com\/help\/en\/wp-json\/wp\/v2\/manual_kb_tag?post=9892"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}