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Questions tagged [captcha]

An anti-spam technique that was developed to block robots from spamming a site. CAPTCHA works by asking the user to answer a question or solve a problem (such as reading a bit of text in an image) that computers were supposedly incapable of solving but humans were.

An anti-spam technique that was developed to block robots from spamming a site. CAPTCHA works by asking the user to answer a question or solve a problem that computers were supposedly incapable of solving but humans were.

Types of CAPTCHA include:

  1. Asking the user to read a bit of hard to read text in an image.
  2. Asking the user to solve a math problem (such as "what is 2 + 2").
  3. Asking the user to answer a question (such as "what is the name of this site?").

Robots have gotten better at reading text in images over the years, which is why some people advocate using option 2 or 3 instead.

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Why do "Registration-bots" exist? What do they gain from registering on my site?

I've been developing some anti-bot procedures for a website, but only because I see others doing it. Why is this necessary? What do the bots gain from registering hundreds of accounts? I'm building an e-commerce website and the only thing registered…
CuriousOne
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Is reCaptcha now basically useless?

Is reCaptcha now basically useless? I have read around the internet that reCaptcha has been broken and spam bots can easily overcome it. Has Google addressed this at all. Do they have any plans to fix it? I cannot find this type of info on the web,…
dqhendricks
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Effective captcha solutions

Possible Duplicate: How can I prevent spam on sites which I control? ReCaptcha is all the rage at the moment, Based on customer/user feedback, what other captcha or general human verification tools have you used for your website? Links to the…
Aiden Bell
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Self hosting of recaptcha-like system to digitise my uploaded books

From wikipedia reCAPTCHA is a system ... that uses CAPTCHA to help digitize the text of books while protecting websites from bots I have a lot of scanned documents that I'd like to convert, and would like to introduce a captcha on my website,…
Craig
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How to tell whether spammers are bots or humans?

How can you tell if the people that are spamming your forum or website are in fact bots or human spammers? Please note that the question is not about preventing spammers. It is to determine if the people that are already spamming are bots or humans.
Andre Backlund
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Clear and concise instructions for an account creation CAPTCHA with MediaWiki?

We get our share spam accounts on our MediaWiki, and we'd like to curb it. According to MediaWiki's Extension:ConfirmAccount: The ConfirmEdit extension can be used (in conjunction with the ConfirmAccount extension) in order to use captchas to stop…
user40589
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How to protect from spam when the legislation forces you to display the email address?

Context I want to protect a ecommerce website from email spam, whilst the legislation in my country makes mandatory to publish an email contact address on ecommerce sites. As an additional constraint, GDPR rules also apply, and some captcha…
OuzoPower
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Can Googlebot crawl reCAPTCHA v2?

I'm building a website that contains certain forms protected by reCAPTCHA v2. Can Googlebot crawl content protected by its own reCAPTCHA v2?
Pedro Lobito
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Chinese bots in my forum

I have a small community forum that doesn't really get posts or any real traffic. The only thing that happens on the regular is bots with Chinese IPs signing up gibberish usernames. Most bots don't make it past the captcha but some do. I try to stay…
T. Thomas
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Localized CAPTCHA

What are effective CAPTCHA solutions that can have localized description, and CAPTCHA text itself is either language-neutral, or can be localized (for Polish language)? It is to be used to protect a kind of contact form. reCAPTCHA (for example)…
Jakub Narębski
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Removing CAPTCHA is harmful for my forms?

I have some services on my site that developed by PHP , it seems having CAPTCHA in my registration form is decreasing registering users , I tend to remove CAPTCHA at least on my registering form , is it harmful for my site?
Ramin
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Can Cloudflare CAPTCHA page pop up when a user fetches non-HTML content such as an image?

For non-HTML content, does Cloudflare still display the Cloudflare CAPTCHA page? A more concrete example Assuming I have a website that hosts images. I have also created a client app that fetches these images via a http-based protocol. Users can…
xuhdev
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Does recaptcha version 3 detect and block Googlebot as a bot?

I am trying to protect my back-end resources using re-captcha from misuse from bots however am not sure of its implication on SEO. There is little information clarifying about this issue. From re-captcha documentations they just say re-captcha…
xaander1
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Does a form review stage decrease submissions by robots?

A relatively recent change to (some?) SE sites is the Review button instead of submitting the question immediately. I have always promoted a review stage. One benefit is that the user gets a chance to check over the submission, but I think that’s…
Manngo
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Recaptcha statistics

Of late recaptcha images have become excessively difficult to decipher. Is there any way to get analytics on unsuccessful attempts before a successful one for your website? I'm pretty certain the numbers are going to be bad and something needs to be…
Syed Ali
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