Turn a folder of photos or scans into one ordered PDF

Receipts for an expense claim, photographs of a damaged delivery, a passport and a utility bill for an application form: plenty of everyday tasks end with "please send this as one PDF". Doing it well takes about a minute.

Order is decided before you export

The image to PDF tool turns each selected image into one page, in the order the list shows. There is no separate sorting step afterwards, so the arranging is the work.

Two habits make it reliable for anything more than a handful of files:

• Name for order. 01-front.jpg, 02-back.jpg, 03-receipt.jpg sorts correctly on every system. Bare numbers do not: 10 sorts before 2, which is why zero padding matters.
• Check the count. Confirm the number of images matches the number of pages you expect before exporting. A missing photo is much easier to notice as a count mismatch than by reading the finished document.

Decide how each image sits on the page

There are two sensible models, and picking the wrong one is the usual cause of an odd-looking result.

Fixed page size. Every page is A4 or Letter, and each image is scaled to fit inside it. This is what you want for anything that will be printed, filed, or combined with other documents. The trade-off is white space around images whose proportions do not match the page.

Image-defined pages. Each page takes the dimensions of its image, so there is no white space at all. This suits screenshots, photo collections, and documents that will only ever be viewed on screen. It produces a PDF with a different page size on every page, which prints unpredictably.

Also decide orientation. A portrait page containing a landscape photo wastes half the sheet; matching orientation per page keeps images as large as possible.

Photographs of documents need correction first

If the images are phone photos of paper, going straight to PDF preserves every flaw: the perspective distortion from holding the camera at an angle, the shadow of your own hand, the desk in the background, and the slight rotation.

Run them through the document scanning tool instead. Edge detection, perspective correction, and contrast normalisation turn a photograph into something that looks like a scan, and the resulting PDF is both smaller and far more legible. It is also the right preparation if you plan to make the document searchable afterwards.

Reserve the direct image-to-PDF path for images that are already correct: real scans, screenshots, exported graphics, and photographs where the photograph itself is the content.

Controlling the file size

Image PDFs get large quickly, and the reason is almost always resolution rather than compression settings.

A modern phone photo is 12 megapixels. Placed on an A4 page, that is roughly 1200 dpi — four times what printing needs and eight times what a screen can show. Ten such photos produce a PDF that will not fit through most mail servers.

The order of operations that works:

1. Resize the images to a sensible resolution before building the PDF. For a full-page image, around 200 dpi is generous on screen and 300 dpi is print-quality.
2. Keep photographic images as JPEG rather than PNG. Lossless compression on a photograph roughly triples the size for no visible benefit.
3. Build the PDF.
4. Only then, if it is still too big, use the compression tool.

Doing it in that order gives a far better result than assembling enormous images and crushing the finished document, and the email size guide covers what limit you are actually aiming for.

Final checks before sending

• Read every page. A photo that is blurry at thumbnail size is unreadable at full size, and you will not find out until the recipient tells you.
• Check for accidental inclusions. Backgrounds capture other documents, screens, and notes. Crop them out rather than hoping nobody looks.
• Check the metadata. Photos carry EXIF data, which can include the capture time and, on many phones, GPS coordinates. Whether that survives into the PDF depends on the pipeline, so strip it if the file is going outside your organisation.
• Confirm orientation. Photos taken in portrait sometimes carry a rotation flag that different software interprets differently.