How to combine photos into one PDF

Most people now photograph documents with a phone instead of scanning them. That works well until you need to send the result. Twelve separate images in an email is awkward for everyone. One PDF is much easier.

The conversion itself is simple. A few choices around it decide whether the result looks neat or messy.

Getting the order right first

Images are almost always sorted by file name, and phone cameras use names like IMG_20260114_093312.jpg. Those sort correctly because the date and time are in the name.

Renamed files are where it goes wrong. page1, page2 … page10 sorts as page1, page10, page11, page2, because alphabetical sorting looks at characters and 1 comes before 2. This is the most common reason a photo PDF comes out in the wrong order.

There are two fixes, and the first one lasts:

• Add zeros to the numbers: page01, page02, page10. Then alphabetical and number order match everywhere.
• Reorder before converting, if the tool lets you drag them.

Check the order before you convert. Rebuilding a PDF because page 10 landed second is easy to avoid.

Page size: the choice people notice

This is where photo PDFs usually look wrong, and there is one cause.

A phone photo is usually 4:3 or 3:4. An A4 page is roughly 1:1.41, which is noticeably taller and narrower. Put a 3:4 photo on an A4 page and you get thick white bands top and bottom.

Two approaches:

Match the page to the image. Each page is exactly the shape of its photo. There are no borders, nothing is wasted, and the PDF looks like a set of photos, which is what it is. This is right for anything that will be read on screen.

Use a standard paper size. Every page is A4 or Letter and the image is fitted inside. There will be white space, but the document prints predictably and files alongside other documents. This is right for anything going to a printer or into a records system.

The mistake is choosing a paper size out of habit for something nobody will print.

Fit or fill

If you do use a standard page, there is a second choice.

Fit puts the whole image on the page, with borders where the shapes disagree. Nothing is lost.

Fill scales the image until it covers the page and crops whatever hangs over the edges. It looks tidier, but it cuts content off. That is fine for a decorative photo and bad for a document, where the cropped part is usually the margin with a reference number in it.

For anything with text on it, fit. Always.

Making the photos worth reading

The conversion can't fix a poor photo, and a few habits when you take it help more than any setting afterwards:

• Flat surface, even light. The biggest single improvement. A page held in one hand curves, and the curve shows.
• Camera parallel to the page. Shooting at an angle produces a trapezoid that no page size will square up.
• Watch your own shadow. Standing between the window and the page is the classic mistake.
• Fill the frame. Cropping later throws away pixels you could have used.

A scanning app is better than the plain camera for this. It finds the page edges and straightens the angle, which the camera app doesn't.

File size

Photo PDFs get large fast. A modern phone photo is 3–6 MB, so twelve of them make a 40–70 MB PDF, which is over most email limits.

Compress it instead of splitting it. Compress PDF saves the images again at a lower quality. For photos of documents you usually can't see the difference, and the size drops a lot. A 50 MB scan bundle routinely comes back under 5 MB and still perfectly readable.

Compress after combining, not before. One pass over the finished document beats twelve passes over the parts.

When the images are already in a folder or a zip

If someone has sent you a zip file, you don't need to unpack it. ZIP to PDF converts everything inside and merges the results in order. It sorts by number, so page2 comes before page10.

Making the text searchable

A PDF of photographs contains no text, only pictures. You cannot search it or copy from it.

If you need that (and for anything going into an archive you probably do), run OCR afterwards. PDF to Text reads the images and gives you the words. It gets back the writing but not the layout, so don't expect a formatted document.

Orientation, when the photos are mixed

A set of photos where some are portrait and some are landscape is awkward, and no setting makes it perfect.

You have two choices:

Pick one orientation and fit everything into it. The landscape shots get white bands above and below, the portrait ones fill the page. Consistent, slightly wasteful, and the right answer when the document will be printed.

Let each page match its image. Nothing is wasted and every photo is as large as possible. The document is uneven to flip through on screen and awkward to print.

For receipts, forms and anything going to somebody official, take the first. For a personal album, the second.

Getting scanned documents to look scanned

Photos of paper look like photos of paper: grey, a little uneven, with a shadow along one edge.

Running each image through Enhance before combining fixes most of that. The black-and-white option turns a grey phone photo of a receipt into something that looks like a scan.

It also makes the PDF much smaller, because a black-and-white image compresses far better than a photo of the same page.

File size, and one number to know

Modern phone photos are 3-5 MB each. Twelve of them is 50 MB before you have added anything.

If the finished PDF has to be emailed, that is over every common email limit. Compress PDF afterwards will usually take it under 10 MB with no visible difference on a receipt or a form, because photographs are exactly what compression handles well.