How to prevent elements in the browser from being hidden?

Web page watermark protection: Respond to hidden browser elements

When designing web page watermarks, in addition to preventing tampering, you also need to consider the browser's ability to hide elements. Users can easily hide elements through the right-click menu of the browser. This article explores how to prevent this behavior, as well as events and style changes triggered by element hiding.

First, in order to prevent users from debugging code through browser developer tools, you can try the following methods to prevent access to developer tools:

1. Disable right-click and F12: Prevent users from opening developer tools by listening to keyboard and right-click events.

    // F12 is prohibited
    document.addEventListener('keydown', e => {
        if (e.keyCode === 123) e.preventDefault();
    });
    // Prohibit the right-click menu document.addEventListener('contextmenu', e => e.preventDefault());

2. Monitor page size changes: The browser window size changes can be used to detect whether the developer tool is open. When the size difference between the visual area and the browser window exceeds the threshold, the developer tool is considered to be open.

    function checkConsole() {
        const threshold = 200;
        const widthDiff = window.outerWidth - window.innerWidth;
        const heightDiff = window.outerHeight - window.innerHeight;
        if (widthDiff > threshold || heightDiff > threshold) {
            console.log('Developer Tools may be open');
            // Add corresponding treatment here, such as warning users or taking other measures}
    }
    window.addEventListener('resize', checkConsole);
    checkConsole();

3. Use debugger statements to infinite recursion (not recommended): This method does not directly detect the developer tool, but uses debugger statements and recursive calls to cause the browser to get stuck when the developer tool is opened. This method is extremely unrecommended because it can seriously affect the user experience and even cause browser crashes.

    // This method is not recommended as it can seriously affect the user experience and may cause browser crashes.
    // Do not use this code in production environment.

The above method is not foolproof, there is always a possibility of being bypassed. A more reliable way is to convert the entire web page into an image, completely preventing the user from removing the watermark elements. Choosing the right strategy depends on the balance of security needs and user experience.

The above is the detailed content of How to prevent elements in the browser from being hidden?. For more information, please follow other related articles on the PHP Chinese website!