Photos to PDF: combine pictures into one file

Handwritten work, made into one file

Most school portals want a single PDF, the format the Library of Congress describes as independent of the software and device used to open it, and a page of maths or a lab notebook usually starts as a few phone photos. Add them in the order the pages go, check each one is upright, choose US Letter so it prints like a normal page, and set a size limit that matches the portal. The tool keeps shrinking the photos, first their resolution, then their JPG quality, until the PDF is under the limit, and tells you the final size.

Photos that read well as a PDF

• Light from the side or above, never from behind the phone, so your own shadow does not fall on the page.
• Flat page, phone parallel to it. A tilted phone makes the bottom of the page smaller than the top.
• Fill the frame with the page, leaving a thin edge of table around it.
• One page per photo. Two pages in one photo come out too small to read.

The options, explained

Option	What it does
Same as each photo	Each PDF page takes the shape of its photo. Best for pictures, not for printing.
US Letter or A4	Every photo is centred on a standard page, turned to landscape when the photo is wider than tall. Best for anything that may be printed.
Margin	White space around each photo on Letter or A4 pages.
Keep the PDF under a size	Tries up to nine steps of smaller photos until the PDF fits. If even the smallest step is too big, it says so: then remove photos or split them into two PDFs.

For nonprofits and offices

Receipts for an expense claim, signed volunteer forms and site photos for a grant report all arrive as phone pictures. One PDF per claim or report is easier to file and to send, and the size limit option keeps it within what email or a funder's portal accepts.