Killing CAPTCHAs with Efficiency

This is a short guide on how to clear CAPTCHAs quickly and efficiently.

Firstly, having a script that alerts you when you have hit a CAPTCHA is invaluable. I recommend this one: https://greasyfork.org/en/scripts/8021-mturk-captcha-alert

When working on a fast moving batch, trying to complete a CAPTCHA within the HIT you are trying to accept can often backfire, as the HIT may be accepted by someone else before you get the chance to finish. Repeat this a few times and you have lost some serious time. For this reason, it is recommended that you get into the habit of completing CAPTCHAs in an external HIT. Popular choices are Jon Brelig or Copytext batches, as they tend to stay up for a long time.

One method of bringing up an external batch for CAPTCHAs is using this script: https://greasyfork.org/en/scripts/10300-captcha-clear

When using this script, pressing a hotkey will bring up a Copytext batch for you to complete the CAPTCHA in. It will close after the CAPTCHA has been completed.

Another method, and my personal preference, is to always have a CAPTCHA batch open in a pinned tab, and using an AHK script to jump to that tab and refresh the page. For example:

Code:

^f1::
sendinput ^2
sleep 50
sendinput {f5}
return

This will jump to the second tab in your browser and refresh when you hit control+f1. Pair with a script that will return the HIT, and you are good to go. I recommend using Brelig with this method as Copytext will send you annoying pop-up messages.

Spoiler: Return Script

Code:

// ==UserScript==
// @name  Captcha Clear Edit
// @namespace  https://greasyfork.org/users/11580
// @version  1.2.2
// @description  This will Auto-return HITs.
// @author  Kadauchi
// @icon  http://www.mturkgrind.com/data/avatars/l/1/1084.jpg?1432698290
// @include  https://www.mturk.com/*
// @exclude  https://www.mturk.com/mturk/findhits?*hit_scraper*
// @grant  GM_log
// @grant  GM_addStyle
// @require  http://code.jquery.com/jquery-2.1.4.min.js
// ==/UserScript==

// Put your HIT's group ID here.
// Default is Copytext Inc. (https://www.mturk.com/mturk/preview?groupId=3T4QHDVBXBLD2A4YZC57CBG4IE9ZWF)
var captcha_hit_group_id = "3USMLONC9E5MDB1GD7ZQ6SDISYR85F";

// Forces quick captcha load.
GM_addStyle("#javascriptDependentFunctionality { display: block !important; }");

// Focuses captcha text box.
if ($("input[name=userCaptchaResponse]").length){
    $("input[name=userCaptchaResponse]").focus();
}

// Returns the HIT.
if(($("input[name=isAccepted][value=true]").length) && ($("input[name=groupId][value="+captcha_hit_group_id+"]").length)){
   $("img[src='/media/return_hit.gif']").click();
}

This is simply a cut down version of Kadauchi's CAPTCHA clear script that will return the HIT for you. Replace the group ID with the group ID of whatever CAPTCHA batch you are using.

When completing a CAPTCHA, be careful not to complete it too fast, or you will be told you entered that CAPTCHA incorrectly and will be given another one (it's dumb.) Around 4-5 seconds should be enough. I always used the Captcha alert dinging to time it, two dings was always enough time.

A few more useful CAPTCHA related scripts:

https://greasyfork.org/en/scripts/5918-mturk-show-captcha-and-accept-button-asap

https://greasyfork.org/en/scripts/907-captcha-counter

@clickhappier has collected useful information on CAPTCHAs here: http://www.mturkcrowd.com/threads/dealing-with-mturk-captchas.118/