CSS :valid Selector

Posted in CSS Tutorial

Updated on Sep 18, 2024

By Mari Selvan

👁️ 3 - Views

⏳ 4 mins

💬 0

Photo Credit to CodeToFun

🙋 Introduction

The :valid selector in CSS is used to select form elements that contain valid values according to their type or constraints.

It is often used with form elements like text inputs, email fields, and more, to provide immediate feedback to users when they input data that meets the required format or pattern.

💡 Syntax

The signature of the :valid Selector is as follows:

Syntax

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:valid {
    /* CSS properties */
}

The :valid pseudo-class applies to input elements that pass validation rules, such as <input>, <textarea>, <select>, and others.

📝 Example

Here is an example of how to use the :valid selector in CSS:

☠️ HTML

HTML

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS :valid Selector Example</title>
    <link rel="stylesheet" href="styles.css">
</head>
<body>
    <form>
        <label for="email">Email:</label>
        <input type="email" id="email" name="email" placeholder="Enter your email" required>

        <label for="age">Age (between 18 and 60):</label>
        <input type="number" id="age" name="age" min="18" max="60" required>

        <button type="submit">Submit</button>
    </form>
</body>
</html>

🎨 CSS

CSS

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/* Style for valid input elements */
:valid {
    border: 2px solid green;
    background-color: #e0ffe0;
}

/* Style for invalid input elements */
:invalid {
    border: 2px solid red;
    background-color: #ffe0e0;
}

In this example:

When the user enters a valid email address and age within the defined range, the input fields are highlighted with a green border and a light green background.
If the user enters invalid data, the input fields are highlighted with a red border and a light red background.

💬 Usage Tips

The :valid selector is often used with form validation to visually indicate when a user's input meets the required rules.
It can be combined with the :invalid selector to style invalid inputs for contrast, ensuring users can easily identify errors and correct them.
This selector works best when used with form controls that have validation constraints such as type="email", pattern, required, or min/max attributes.

⚠️ Common Pitfalls

Remember that the :valid pseudo-class does not work on all elements; it is typically used for form controls like <input>, <textarea>, and <select>.
Be aware that validation rules depend on the browser, so test your form on different browsers to ensure consistent behavior across platforms.
Avoid over-reliance on the :valid selector alone for form validation. It is best combined with JavaScript for more complex or custom validation rules.

🎉 Conclusion

The :valid selector is a valuable tool for form validation in CSS, allowing developers to provide users with real-time feedback on the correctness of their inputs.

By styling valid inputs with distinct visual cues, you can create a more intuitive and user-friendly form experience. Paired with the :invalid selector, it ensures that users can easily identify and correct mistakes, enhancing overall usability.