How I Built a PDF to JPG Converter That Renders at 600 DPI Inside a Browser Tab

The complete engineering story behind high-resolution PDF-to-image conversion using PDF.js, canvas memory management, and device-adaptive processing Most online PDF to JPG converters cap output at 150 DPI. Some go to 300 DPI if you pay. Very few reach 600 DPI, and those that do require uploading your file to their servers. The PDF to JPG converter inside ihatepdf.cv supports up to 600 DPI output — completely free, with zero server upload. Every pixel is rendered locally in your browser. Here's exactly how it works, why 600 DPI matters, and what engineering problems had to be solved to make it work on devices ranging from an iPhone to a 32GB workstation. Why DPI matters for PDF to image conversion DPI stands for dots per inch — it describes how many pixels represent each inch of the original document. 72 DPI is the browser's base resolution. One CSS pixel equals one device pixel at 1× zoom. This is what you get from a naive canvas.toBlob() call without any scaling. Fine for a thumbnail.