Captcha generator

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Type: captcha

v1.1.1 2015-09-11 15:23 UTC


Captchas examples


With composer :

    "require": {
        "gregwar/captcha": "1.*"


You can create a captcha with the CaptchaBuilder :


use Gregwar\Captcha\CaptchaBuilder;

$builder = new CaptchaBuilder;

You can then save it to a file :



Or output it directly :


header('Content-type: image/jpeg');

Or inline it directly in the HTML page:

<img src="<?php echo $builder->inline(); ?>" />

You'll be able to get the code and compare it with a user input :


// Example: storing the phrase in the session to test for the user 
// input later
$_SESSION['phrase'] = $builder->getPhrase();

You can compare the phrase with user input:

if($builder->testPhrase($userInput)) {
    // instructions if user phrase is good
else {
    // user phrase is wrong


You can use theses functions :

  • __construct($phrase = null), constructs the builder with the given phrase, if the phrase is null, a random one will be generated
  • getPhrase(), allow you to get the phrase contents
  • setDistortion($distortion), enable or disable the distortion, call it before build()
  • isOCRReadable(), returns true if the OCR can be read using the ocrad software, you'll need to have shell_exec enabled, imagemagick and ocrad installed
  • buildAgainstOCR($width = 150, $height = 40, $font = null), builds a code until it is not readable by ocrad
  • build($width = 150, $height = 40, $font = null), builds a code with the given $width, $height and $font. By default, a random font will be used from the library
  • save($filename, $quality = 80), saves the captcha into a jpeg in the $filename, with the given quality
  • get($quality = 80), returns the jpeg data
  • output($quality = 80), directly outputs the jpeg code to a browser
  • setBackgroundColor($r, $g, $b), sets the background color to force it (this will disable many effects and is not recommended)
  • setBackgroundImages(array($imagepath1, $imagePath2)), Sets custom background images to be used as captcha background. It is recommended to disable image effects when passing custom images for background (ignore_all_effects). A random image is selected from the list passed, the full paths to the image files must be passed.
  • setInterpolation($interpolate), enable or disable the interpolation (enabled by default), disabling it will be quicker but the images will look uglier
  • setIgnoreAllEffects($ignoreAllEffects), disable all effects on the captcha image. Recommended to use when passing custom background images for the captcha.
  • testPhrase($phrase), returns true if the given phrase is good
  • setMaxBehindLines($lines), sets the maximum number of lines behind the code
  • setMaxFrontLines($lines), sets the maximum number of lines on the front of the code

Symfony 2 Bundle

You can have a look at the following repository to enjoy the Symfony 2 bundle packaging this captcha generator :


This library is under MIT license, have a look to the LICENSE file