Web Workers allow you to run JavaScript in background threads, separate from the main browser thread. When applying heavy image filters (like blur or convolutions), the main thread would normally freeze, making the page unresponsive. A Web Worker processes the pixel data without blocking the UI, so you can still scroll, click, and interact with the page.

The demo includes grayscale, sepia, invert, brightness, contrast, box blur, sharpen, edge detection (Sobel), and emboss. Among these, Box Blur and Edge Detection are the most computationally heavy because they require convolution with neighboring pixels, making them perfect for stressing the Web Worker.

Yes, Web Workers are supported in all modern browsers, including Chrome, Firefox, Safari, Edge, and their mobile versions. This demo requires a browser with full worker support, which covers over 97% of global users.

No. All processing happens entirely within your browser. The image is never sent to any remote server. This tool respects your privacy and can even work offline once loaded.

The Web Worker reports its progress after processing each row of pixels. The main thread updates the progress bar in real time, giving you visual feedback without freezing the UI.

Yes. Click the "Cancel" button to immediately terminate the Web Worker. This stops the processing and frees resources, allowing you to start a new task right away.

Besides keeping the page interactive, Web Workers enable parallel processing, making your web application feel fast and responsive even under heavy load. This is essential for professional image editors, real-time filters, or any compute-intensive web tool.