How the conversion works
The PDF is opened with pdf.js, Mozilla's open-source PDF reader. Each page you asked for is drawn onto a white canvas at your chosen resolution, the same way a PDF viewer draws it on screen, and the canvas is saved as a JPG. The page size in the PDF sets the pixel size of the picture: PDF pages are measured in points, 72 to the inch.
Pixels across = page width in points ÷ 72 × DPI
Pixels down = page height in points ÷ 72 × DPI
Worked example: a Letter page at 150 DPI
A US Letter page is 612 × 792 points, which is 8.5 × 11 inches. At 150 DPI that is 8.5 × 150 = 1275 pixels across and 11 × 150 = 1650 pixels down, about 2.1 megapixels. That is sharp on any phone or laptop screen and fine for an email attachment. Double the DPI to 300 and the image has four times as many pixels, 2550 × 3300, which is what a printer needs for crisp text.
Settings, and when to change them
| Setting | Use it for |
|---|---|
| 72 DPI | Thumbnails and quick previews. Small text may be hard to read. |
| 150 DPI | Most uses: email, websites, slides, sharing in a chat app. |
| 300 DPI | Printing, or zooming in on fine print, maps and drawings. |
| Custom, 36 to 600 DPI | Matching a size a form or website asks for. |
| JPG quality | 85% is the default. Raise it toward 100% for diagrams with thin lines on flat color; lower it to make files smaller. |
JPG or PNG?
JPG files are smaller and open everywhere, which makes them the better choice for scanned pages and pages with photos. JPG compression can leave faint smudges around sharp black text on white, though. For text-heavy pages, charts or anything you will edit later, PDF to PNG keeps every pixel exact, at the cost of bigger files. JPG has no transparency, so pages always come out on white.
Privacy
The page loads its code once, then does all the work on your device. There is no upload, no account and no copy on a server. You can check it yourself: load this page, turn off Wi-Fi, and convert a file.
Limits
Large PDFs are converted one page at a time, so a 300-page file works, but every finished image is kept in memory until you leave the page. On a phone, convert big documents in batches using the Pages box. To go the other way and turn photos into a PDF, use JPG to PDF.
Questions people ask
Is my PDF uploaded to convert it?
No. The pages are drawn by pdf.js, the same open-source PDF reader Firefox uses, running inside this page on your device. The JPG files are made in your browser and saved to your Downloads. Nothing is sent to a server, so it is safe for bank statements, tax forms and signed contracts.
Which resolution should I pick?
150 DPI is right for most things: email, web pages, slides and reading on a phone. Choose 300 DPI when the image will be printed or when you need to zoom in on small print. 72 DPI makes small, quick previews. A Letter page comes out at 1275 × 1650 pixels at 150 DPI and 2550 × 3300 pixels at 300 DPI.
Can I convert just one page, or a few?
Yes. Type the pages in the Pages box: 3 for one page, 1-3, 7 for a few, or 10- for page 10 to the end. Leave it empty to convert every page. Each page becomes its own JPG.
How do I download all the pages at once?
When there is more than one image, choose "Download all as ZIP" to get a single ZIP file with every page inside, named in page order (report-page-01.jpg, report-page-02.jpg and so on). Or download pages one at a time with the button under each preview.
Why did some pages come out at a lower resolution than I chose?
Browsers limit how big an image they can draw. This tool keeps each page under about 30 megapixels on a computer and 5 megapixels on a phone or tablet, and lowers the resolution of any page that would go over. A Letter page at 300 DPI is 8.4 megapixels, so on a phone it comes out at about 230 DPI instead. The status line tells you when this happened.
Can it open a password-protected PDF?
Yes, if you know the password. The page asks for it, uses it only to read the file on your device, and never sends or saves it. The JPG images it makes have no password.