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Turn phone photos of a document into one small PDF

How to photograph pages so they are easy to read, and how to combine them into a PDF small enough to email or upload.

Why photo PDFs end up huge

Landlords, schools, banks and employers often ask for a document as one PDF. The quickest route is to photograph each page with your phone and combine the photos, but the obvious ways of doing that produce enormous files. Each phone photo is about 12 megapixels and 4 to 5 MB, and many apps place every photo in the PDF exactly as it is.

We tested with ten 12-megapixel phone photos totalling 50.2 MB. Placed in a PDF unchanged, they make a PDF of roughly the same size, around 50 MB. That is twice the 25 MB attachment limit of Gmail, and many upload forms allow only 5 or 10 MB.

How much resolution a page actually needs

Printing and on-screen reading need far fewer pixels than a phone camera takes. An A4 page at 150 dots per inch, plenty for typed text, is 1240 by 1754 pixels, or about 2.2 megapixels. A US Letter page at the same resolution is 1275 by 1650 pixels. A 12-megapixel photo carries more than five times the pixels the page can show.

So the fix is to resize each photo to its page at a sensible resolution, then store it as a well-compressed JPG inside the PDF. Smushify does exactly that, which is how the same ten photos come out at 1 to 2 MB instead of 50.

Taking photos that read well

Good photos make a better PDF than any setting can. Put the page on a flat surface with even light, ideally daylight from a window, and avoid your own shadow by holding the phone slightly to the side. Hold the phone parallel to the page, directly above it, so the text is square rather than slanting away. Fill the frame with the page and leave a small margin around it.

Smushify places each photo on its page as it is: it does not straighten pages or crop away the table underneath. If a photo is crooked or has a lot of background, crop it first in your phone's Photos app. If you have not taken the photos yet, the document scanners in the iPhone Notes app and in Google Drive on Android straighten pages as you shoot and make a PDF themselves; Smushify is for the photos you already have.

Combining the photos into a PDF

Open the converter below, which starts in PDF mode, and add your photos. JPG, PNG, WebP and iPhone HEIC photos all work. Put the pages in order with the up and down arrows, or remove a page you do not need. Choose a page size: A4 or Letter for documents that may be printed, or Fit to image to keep each photo's own shape. Portrait and landscape photos each get a page in their own orientation, and photos taken sideways are turned the right way up.

Then pick a quality preset. Document (150 dpi, quality 70) suits typed and printed pages. Photo (220 dpi, quality 80) keeps more detail for photographs and very small print. Smallest (100 dpi, quality 55) is for when size matters more than anything else. Turn on Greyscale for black-and-white documents: it makes the file smaller and the text often looks crisper. You see an estimated size before you build, then the real size with a Download button.

What sizes to expect

Here is what our ten test photos (50.2 MB in total) produced on A4 pages with each setting; each PDF took a few seconds to build. Pages of plain text usually come out smaller than these photographs, because text on white paper compresses very well.

When the PDF has to fit a limit

If an upload form says "maximum 2 MB", set a target size for the whole PDF instead of guessing a preset. Smushify lowers the quality of every page together, then the resolution if it has to, until the PDF fits, and tells you which quality and resolution it used. If even the smallest version is too big, it says so and suggests Greyscale, fewer pages or a larger limit.

Private by design

Documents are often the most private files people handle: payslips, contracts, IDs and medical letters. Smushify builds the PDF inside your browser, so the photos are never uploaded, and the finished PDF carries no camera or location details from the photos. If you need to sign the PDF or fill it in afterwards, open it in SecureSignFree, our free PDF signing site.

Open the images to PDF converter

Try it: Images to PDF

Open the Images to PDF converter. It runs in your browser, so nothing is uploaded.

Frequently asked questions

Can I scan a document to PDF without an app?

Yes. Take photos with your phone's camera, then open Smushify in the phone's browser and combine them into a PDF there. Nothing needs to be installed and nothing is uploaded.

Which page size should I choose?

A4 in most of the world and Letter in the US and Canada, if the document may be printed. Fit to image makes each page exactly the shape of its photo, which suits receipts and screenshots.

Will the text still be readable?

At the Document preset (150 dpi) normal-sized print stays sharp. Choose Photo (220 dpi) for very small print, and always take the photos in good light.

Are my files uploaded anywhere?

No. Smushify converts everything inside your browser using WebAssembly. Your files are never sent to a server, so it is safe for private photos and documents.

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