How can I detect an image that is not found? | ecode10.com

How can I detect an image that is not found?

There are several ways to detect a broken image...

JAVASCRIPT

Thursday, April 16, 2026

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There are several ways to detect a broken image in JavaScript, ranging from simple inline attributes to modern event listeners.

Using the onerror Event (The Easiest Way)

The onerror event fires as soon as the browser fails to load the image. You can use this to hide the image or swap it with a placeholder.

Inline HTML:

<img src="broken-link.jpg" onerror="this.src='placeholder.png';">

Code 1 - HTML

Using JavaScript Event Listener:

This is the preferred method for clean code.

const img = document.querySelector('img');

img.addEventListener('error', function() {
    console.log('The image failed to load.');
    this.src = 'fallback-image.jpg'; // Replace with a default image
    // this.style.display = 'none';   // Or just hide it
});

Code 2 - JavaScript

Checking if an Image is Already Broken

If the page has already loaded and you want to check the status of an image (for example, after a script finishes running), you can check the complete and naturalWidth properties.

function isImageValid(imgElement) {
    // If the browser hasn't finished checking the image, it's not "complete"
    if (!imgElement.complete) {
        return true; // Still loading...
    }

    // If the image loaded but has a width of 0, it is broken
    if (imgElement.naturalWidth === 0) {
        return false;
    }

    return true;
}

const myImg = document.getElementById('myImage');
if (!isImageValid(myImg)) {
    console.log("Image is broken!");
}

Code 3 - JavaScript - Image is Alrady Broken

Handling Multiple Images (Bulk Detection)

If you want to detect every broken image on a page and replace them all at once:

document.querySelectorAll('img').forEach(img => {
    img.addEventListener('error', function() {
        this.src = 'https://placeholder.com';
        this.alt = 'Image failed to load';
    });
});

Code 4 - Bulk Detection

Using "Event Capture" (For Dynamic Content)

If you are adding images to the page dynamically (via AJAX or React/Vue), a standard event listener might not catch them. You can use Event Capturing on the window to catch all image errors globally.

window.addEventListener('error', function(event) {
    if (event.target.tagName.toLowerCase() === 'img') {
        console.log('Broken image detected:', event.target.src);
        event.target.src = 'fallback.png';
    }
}, true); // The "true" here is critical to enable capturing

Code 5 - For dynamic content