Turning a PDF into images is three decisions — how sharp, which format, which pages — and one button. Get the three decisions right and a 40-page report becomes a folder of clean images in seconds, in your browser, with the file never leaving your machine. Here are the numbers behind each choice.
PDF pages are measured in points (1/72 inch), and rendering multiplies by DPI ÷ 72 to get pixels. That makes the pixel counts predictable:
| DPI | A4 page | Letter page | Use it for |
|---|---|---|---|
| 72 | 595 × 842 | 612 × 792 | Thumbnails, previews |
| 96 | 794 × 1123 | 816 × 1056 | Screens, email, chat |
| 150 | 1240 × 1754 | 1275 × 1650 | Everyday viewing, sharing |
| 200 | 1654 × 2339 | 1700 × 2200 | Small type, fine detail |
| 300 | 2480 × 3508 | 2550 × 3300 | Printing, archiving |
The trap is over-rendering. Doubling DPI doubles both dimensions, so pixel count — and file size — roughly quadruples: an A4 page is about 2.2 million pixels at 150 DPI and 8.7 million at 300. If the image will be seen on a screen, 150 is already sharper than most displays show; save 300 for paper.
JPEG shines on pages with photographic content — scans, gradients, photos — where it delivers a fraction of PNG's size with no visible difference at quality 85 or so. PNG wins on flat graphics: screenshots, charts, text on solid color, where JPEG's compression smudges crisp edges and PNG keeps them pixel-perfect (and supports transparency). For a typical text document with a logo, either works; JPEG at 85 is the sensible default.
Most converters ask for a page range, and it's worth using. A range like 1-3,7 pulls the first three pages plus page seven — the signature page of a contract, the diagram everyone keeps asking for, the one slide-worthy figure. Export just those, and you skip rendering (and downloading) the 53 pages nobody needed. Full-document exports should arrive as a single ZIP with files named page-1.jpg through page-N.jpg, so order is obvious when they land in a folder.
A PDF page is usually vectors and text objects — resolution-independent. An image is a fixed grid of pixels. Converting trades the former for the latter: text stops being selectable, stops being searchable, and stops re-sharpening when you zoom. None of that matters for a chat attachment or a slide image; all of it matters if someone later needs to copy an address out of the file. Export images when images are the goal; keep the PDF as the source of truth.
Pick DPI and format, choose pages, get a single image or a ZIP — free, private, entirely in-browser.
Open PDF to JPG →The round trip is free too: JPG to PDF rebinds images into a document, Compress PDF trims an oversized result, and PDF Add Text stamps a date on pages before you export them.
150 DPI JPEG for sharing, 300 DPI for paper, PNG for flat graphics, and page ranges for everything you don't actually need. The math is stable — DPI ÷ 72 times the page's points — so an A4 page is 1240 × 1754 pixels at 150 DPI every single time. Choose once, convert, done.
96 DPI for screens and email, 150 DPI for everyday viewing, 300 DPI for printing or deep zooming. On an A4 page that's 794x1123, 1240x1754, and 2480x3508 pixels respectively. Above 300 DPI you mostly inflate file size, because the source PDF only carries so much detail to begin with.
It rasterizes. Vector text and sharp lines become a grid of pixels, so quality depends on the DPI you pick: 300 DPI keeps normal text print-sharp, 72 DPI makes small type fuzzy. The image also loses selectable text, searchability, and any embedded structure. Photos inside the PDF keep roughly their native detail if your DPI doesn't shrink them.
DPI scales both dimensions, so pixel count grows with the square. A4 at 150 DPI is 1240x1754 (about 2.2 million pixels); at 300 DPI it's 2480x3508 (about 8.7 million) — four times the pixels and roughly four times the file size. If you only need extra width, export at 150 and let the viewer scale, or crop instead of raising DPI.
Use the page range field: 1-3,7 exports pages one through three plus page seven. That's the fast path when a 60-page contract needs one signature page as an image. Leave the field empty to export every page, which typically arrives as a single ZIP with one file per page.