PDF to JPG

What this is good for

Putting a page into a slide deck or a document. Presentation software handles images far more gracefully than embedded PDFs.

Sending one page instead of a whole document. Render, pick the page you need, send the image.

Getting around an upload form that will not take PDFs. More common than it should be, especially on older government portals.

Reading a PDF on a device with no PDF reader. Rare now, but e-readers and some kiosks still prefer images.

Resolution, concretely

PDF pages are described in points — 72 to the inch — so the render scale maps directly onto DPI. For a standard A4 page (595 × 842 points):

Text becomes comfortably readable at 144 dpi and genuinely sharp at 216. Going to 300 only pays off if the result will be printed.

How the rendering works

pdf.js parses the document in its own worker thread and produces drawing operations; those are painted onto a canvas, and the canvas is encoded to JPEG or PNG. This is the same pipeline Firefox uses to show you a PDF, so what you get out matches what a browser shows.

Pages are processed one at a time and each canvas is released immediately afterwards, which is why a long document does not exhaust memory. If you cancel mid-way, the pages already rendered stay available to download.

Encrypted and unusual files

Password-protected documents cannot be opened without their password, and this tool does not try to work around encryption. Open the file in a reader with the password and save an unlocked copy first.

Documents that fail to parse entirely are usually truncated downloads. If a file opens in one reader and not here, re-downloading it from the source often resolves it.

After rendering

Page images at 300 dpi are large. If you are emailing them or attaching them to a form, the result screen hands the whole set to the compressor or the resizer in one click, and your rendered pages travel with it.