PDF toolsA PDF page and a JPG image serve different purposes. A PDF keeps text selectable, searchable and crisp at any zoom level, which is exactly wrong for the few situations where you need a page as a flat picture instead: pasting one page into a slide deck or a design tool that only accepts images, posting a page to social media, or using a page as the input to something that expects a photo rather than a document.
Converting a page to an image
PDF to JPG renders each page of the file as an image at the resolution you choose, in your browser. A single-page PDF becomes one JPG; a multi-page PDF becomes a ZIP file with one JPG per page, named in order.
Choosing a resolution
Resolution controls both sharpness and file size. For a page that will stay on screen, such as a social post or a slide, 150 dpi is usually sharp enough and keeps the file small. For something that might be printed, or zoomed into, 300 dpi holds up better. The trade-offs, and what dpi actually measures, are covered in DPI explained. If you'd rather keep the image at a fixed pixel size regardless of dpi, the paper size calculator shows the pixel dimensions for common page sizes at a given resolution.
Going the other way: photos into a PDF
The reverse job, turning one or more photos into a single document, is just as common: a few pages of a contract shot with a phone camera, or a handful of receipt photos that need to travel as one file instead of several. JPG to PDF combines any number of images into a single PDF, one image per page, in the order you arrange them. For photos taken with an iPhone that are saved as HEIC rather than JPG, HEIC to PDF does the same conversion directly, without needing to convert the format first.
Questions
What resolution should I use?
150 dpi for anything staying on screen, 300 dpi if it might be printed or viewed zoomed in. Going much higher mainly increases file size without a visible difference.
Does converting to JPG make the text blurry?
The text is rendered as part of the image at the resolution you pick, so it's as sharp as that resolution allows, but it's no longer selectable or searchable text the way it is in the original PDF.
Can I convert just one page out of a long PDF?
Yes, pages can be extracted first with Extract pages, then converted, or convert the whole file and use only the JPG you need from the resulting set.
Is there a limit to how many photos I can combine into one PDF?
No fixed limit. Everything runs on your device, so dozens of photos are fine; very large, high-resolution photo sets may be slower on an older phone.