How to Add a Simple Popup Notification to Your WordPress Site Without Plugins

Adding a quick popup to your WordPress site can be a great way to deliver important messages, announcements, or offers – without slowing down your site or installing yet another plugin.

Here’s a lightweight, performance-friendly solution using just a bit of JavaScript, HTML, and CSS. No external libraries. No dependencies, No bloat. Just change the text of the message and add it as below.

What This Popup Does:

• Shows up only once every 30 days per visitor
• Can be used on any page (except the homepage, in this example)
• Fully customizable design and text
• Doesn’t rely on any plugins (ideal for speed-focused sites)

How It Works:

• A bit of JavaScript sets a cookie when the user closes the popup.
• The popup HTML is injected via functions.php.
• Basic CSS handles the styling and layout.

JavaScript (add to footer.php):

<script>
  function setCookie(name, value, days) {
    const expires = new Date(Date.now() + days*24*60*60*1000).toUTCString();
    document.cookie = name + "=" + value + "; expires=" + expires + "; path=/";
  }

  function getCookie(name) {
    const value = "; " + document.cookie;
    const parts = value.split("; " + name + "=");
    if (parts.length === 2) return parts.pop().split(";").shift();
  }

  window.addEventListener('load', function() {
    if (!getCookie('oswpopup_shown')) {
      document.getElementById('osw-popup').style.display = 'flex';
    }
  });

  document.addEventListener('click', function(e) {
    if (e.target.id === 'osw-popup-close') {
      document.getElementById('osw-popup').style.display = 'none';
      setCookie('oswpopup_shown', 'yes', 30);
    }
  });
</script>

PHP (add to functions.php of your child theme):

function osw_custom_popup_html() {
    ?>
    <div id="osw-popup" style="display:none;">
      <div id="osw-popup-content">
        <p><strong>Your text</strong><br>
        Your big text</p>
        <button id="osw-popup-close">Got it!</button>
      </div>
    </div>
    <?php
}
add_action('wp_footer', 'osw_custom_popup_html');

CSS (add to Appearance>Customize>Additional CSS):

#osw-popup {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
}

#osw-popup-content {
  background: #fff;
  padding: 2rem;
  max-width: 400px;
  border-radius: 10px;
  text-align: center;
  box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

#osw-popup-content button {
  background-color: #000;
  color: #fff;
  border: none;
  padding: 0.7rem 1.5rem;
  margin-top: 1rem;
  cursor: pointer;
  font-weight: bold;
  border-radius: 5px;
}

/* Optional: Hide popup on homepage */
.home #osw-popup {
  display: none !important;
}

Written by Anton, founder of OSWOptimize and an SEO & Web Performance expert with over 14 years of hands-on experience. I specialize in fixing Core Web Vitals, CLS issues, and boosting search rankings for WordPress websites.

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