What We Want to Achieve

We want the text area where users input text, such as in a search box, to automatically resize itself when the amount of text exceeds the initial size.

Code

※ Feel free to change the versions of Bootstrap and jQuery to your preference.

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Hello Resizable Textarea</title>
<link rel="shortcut icon" href="favicon.ico" type="image/x-icon">

<!-- jQuery 3.5.1 -->
<script src="https://code.jquery.com/jquery-3.5.1.js"
	integrity="sha256-QWo7LDvxbWT2tbbQ97B53yJnYU3WhH/C8ycbRAkjPDc="
	crossorigin="anonymous"></script>

<!-- bootstrap 5 -->
<link
	href="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/css/bootstrap.min.css"
	rel="stylesheet"
	integrity="sha384-EVSTQN3/azprG1Anm3QDgpJLIm9Nao0Yz1ztcQTwFspd3yD65VohhpuuCOmLASjC"
	crossorigin="anonymous">

<!-- Bootstrap Icons -->
<link href="https://cdn.jsdelivr.net/npm/bootstrap-icons/font/bootstrap-icons.css" rel="stylesheet">

<script type="text/javascript" class="init">
$(document).ready(function() {
    const textarea = document.querySelector('.input-group textarea');
    function autoResize() {
    	textarea.style.height = 'auto';
    	textarea.style.height = this.scrollHeight + 'px'; // Set to scroll height
    }
    textarea.addEventListener('input', autoResize); // Adjust size on input
    autoResize();
});
</script>

</head>

<body class="m-3">
    <div class="container mt-5">
        <div class="row">
            <div class="col">
                <div class="input-group mb-3">
                    <textarea class="form-control" placeholder="Search criteria" aria-label="Search" rows="1" ></textarea>
                    <button id="btn_search" type="submit" class="btn btn-primary"><i class="bi bi-search"></i></button>
                </div>
            </div>
        </div>
    </div>
</body>
</html>

Comment: It would be great if this becomes standard in HTML.