In this post I want explain how to create and implement a Captcha in PHP. We are using inbuilt features available in PHP for creating an image. This is very simple and basic tutorial and we are not using any custom fonts for generating captcha image. Captcha code used to avoid spam/abuse or auto-submission.  The random value of this image appears inside the generated CAPTCHA image which can be refreshed if not readable. This Captcha Code you can implement on the website level as well on any specific page like contact form.

Live Demo of PHP Captcha and source code download free –

Demo  Download Source


< ?php
$ranStr = md5(microtime());
$ranStr = substr($ranStr, 0, 6);
$_SESSION['cap_code'] = $ranStr;
$newImage = imagecreatefromjpeg("cap_bg.jpg");
$txtColor = imagecolorallocate($newImage, 0, 0, 0);
imagestring($newImage, 5, 5, 5, $ranStr, $txtColor);
header("Content-type: image/jpeg");

Here we are storing a captcha code in SESSION variable and while verifying we have to compare the session variable with user entered data.

$_SESSION[‘cap_code’] – is having actual captcha code
$_POST[‘captcha’] – user entered captcha code

< ?php
$cap = 'notEq';
    if ($_POST['captcha'] == $_SESSION['cap_code']) {
        // Captcha verification is Correct. Do something here!
    } else {
        // Captcha verification is wrong. Take other action

Complete Captcha working code:

< !DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

        Captcha - PHP | Jquery

PHP Captcha Code

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