PDF to JPG turns selected pages of a PDF into standalone JPG images, rendered entirely on your own device. A quick, low-resolution preview of every page appears as soon as you drop in a file, generated on the main thread with pdf.js so you can browse and select pages instantly.

The actual export is a separate, heavier step, so it's handled differently: once you pick your pages and a quality tier, rendering happens inside a dedicated background worker at the full resolution that tier calls for, using an off-screen canvas. That distinction matters because high-resolution rendering is genuinely CPU-intensive work — keeping it off the main thread means the rest of the page (scrolling, clicking other buttons, watching progress) stays responsive even while a Maximum-quality export of a large document is running.

Before you commit to an export, each quality tier shows a rough estimated file size per page, based on the selected page's dimensions and that tier's target resolution and JPEG compression setting — enough to sanity-check whether Standard is good enough or Maximum is worth the extra time and space. Standard is tuned for quick previews and screen viewing, High is a good middle ground for most sharing needs, and Maximum is meant for print or close zooming.

Once export finishes, single-page selections download directly as a `.jpg`; multi-page selections are bundled into one `.zip` so you're not clicking through downloads one at a time. As with every step before it, the source PDF, the rendered images, and the zip archive all stay in your browser's memory for the duration of the operation.