reCAPTCHA vs other captcha systems

Question

What is a good reason to choose reCAPTCHA over a well known and tested captcha generator on the server. Is it just philanthropy (helping with digitizing texts) or are there other good reasons.

Answer 1

We need to register our IP address on which server would be running. Its seems some what risky. So we might be required to change registration work flow in case of use of reCAPTCHA.

Answer 2

This is an old threat but I would just like to confirm that in my case we used reCAPTCHA on a number of Drupal 6 websites in combination with the Honeypot module. We did that to stop automated spam user registrations.

I presume these user accounts were being created automatically by desktop applications such as SEnuke XCr and XRumer with the aim of then posting spam. They create the user account but they rarely do anything further but I found it annoying. Further reading on this subject can be found here: How to prevent spam user registrations? (links to an article on Drupal.org).

I can confirm that the above reduced my spam user registrations from a little over 100 a day to none at all.

Answer 3

The question was "why should I use it"; that question must include "why shouldn't I use it", so some criticisms:

Recaptcha volunteers your users to be OCR monkeys, without bothering to ask their opinion.

It requires that you advertise recaptcha in the captcha widget, which isn't always appropriate.

It's a web service, which means there's no hard guarantee it'll still exist a week or a year or two years from now. (Google has crippled or removed public, widely-used APIs in the past, such as their translation API.)

It only supports web pages, loading everything with scripts and iframes. It doesn't have a proper API, so if you ever want to have an iOS or Android app that logs into your system, and need to show a captcha there, you'll be out of luck.

You have no control over the complexity of the generated captcha. Captchas always have a tradeoff between how hard they are to read and how difficult they are to OCR. There are no knobs to adjust, based on how important stopping robots is to your use case. If they decide to make the captchas much harder to read (which they've done at times), and this becomes a nuisance to your users, there's nothing you can do about it.

Answer 4

reCAPTCHA is rather neat. Not only does it stop spammers but it helps digitize books. Each word that appears in the captcha has actually been scanned in from a book but sometimes the character recognition is off so the computer my save some gibberish of a sentence without knowing any better.

See the image off their site:

By making people type in what they think the word is, it helps create a digital copy of the book or word that was scanned with accuracy while at the same time checking what the user submit, comparing it to other's submissions, and determining if the user is human or not.

For that reason I use reCAPTCHA. I'm not just selfishly protecting my site, I'm providing a service for others.

Not only that but it's fairly simple to implement and provided by a reliable company (Google).

Answer 5

reCAPTCHA is quite good. Most other generators are broken easily while reCAPTCHA usually gets good scores.

Another good thing is that it has the accessiblity button so that it would read the text.