📘 Lesson · Lesson 50

CAPTCHA Validation

About

A CAPTCHA stops spam bots by asking the user to prove they are human. Here is a simple text CAPTCHA.

Generate CAPTCHA

session_start();
$code = substr(str_shuffle("ABCDEFGHJKMNPQRSTUVWXYZ23456789"), 0, 5);
$_SESSION["captcha"] = $code;
echo "Type this code: <b>$code</b>";

Verify CAPTCHA

if (strtoupper($_POST["captcha"]) === $_SESSION["captcha"]) {
    echo "Correct! You are human.";
} else {
    echo "Wrong code, try again.";
}

For Production

For real sites, Google reCAPTCHA is stronger and easier than building your own. Use it for important forms.

Summary

Generate a random code, store in session, ask the user to type it.
Compare on submit; use Google reCAPTCHA for production sites.

परिचय

CAPTCHA spam bots को रोकता है, user से इंसान होने का सबूत माँगकर। यह रहा simple text CAPTCHA।

CAPTCHA Generate करें

session_start();
$code = substr(str_shuffle("ABCDEFGHJKMNPQRSTUVWXYZ23456789"), 0, 5);
$_SESSION["captcha"] = $code;
echo "Type this code: <b>$code</b>";

CAPTCHA Verify करें

if (strtoupper($_POST["captcha"]) === $_SESSION["captcha"]) {
    echo "Correct! You are human.";
} else {
    echo "Wrong code, try again.";
}

Production के लिए

असली sites के लिए Google reCAPTCHA अपना बनाने से मज़बूत और आसान है। ज़रूरी forms के लिए use करें।

सारांश

Random code generate करें, session में store करें, user से type करवाएं।
Submit पर compare करें; production sites के लिए Google reCAPTCHA use करें।

← Back to PHP Tutorial