How to convert images to PDF for a document upload
Portals demand PDF, you have a phone full of photos, and the small print mentions a size limit. The fiddly parts are the details.
Updated 2026-10-08 · no upload, works offline once loaded
Upload forms ask for a PDF because it gives the receiving system something predictable: a fixed number of pages at a known size, in an order that will not change. A folder of photos gives it neither. Converting is straightforward, but a few details decide whether the submission is accepted.
Getting the page size right
A4 is the standard almost everywhere outside North America; Letter is the standard there. If the form does not say, A4 is the safer default for anything international.
Your photo is placed onto the page and scaled to fit. It is not cropped, so the whole image is visible — with margins at the sides or top and bottom depending on the shape of the photo.
Convert images to PDF Combine photos or scans into one clean PDF document.Getting the order right
The order you arrange the images becomes the page order. This is the step where submissions fail: a form that expects identification first and proof of address second will be rejected if the pages are reversed, and the reviewer will not guess what you meant.
Arrange the images before combining, and check the resulting PDF by opening it and paging through. One misordered page is a rejected application and a wait of days.
Hitting the file size limit
Portals commonly cap uploads at 2 MB or 5 MB, and photographs are large. A modern phone camera produces several megabytes per image, so two photos can exceed a 5 MB limit on their own.
Two things bring the size down, and it is worth knowing which you need:
- Compress the images first. Re-encoding a phone photo at a moderate quality setting typically removes most of the size with no visible difference on a document. Use the image compression tool before combining.
- Reduce the dimensions. A form that displays your ID at 600 pixels wide gains nothing from a 4000-pixel original. Resizing is often the larger win of the two.
Do the image work first, then combine — shrinking the images inside an already-built PDF is harder than shrinking them before.
What the resulting PDF will and will not do
The document will contain photographs of pages, not text. That means it will not be searchable and its text cannot be selected or copied.
If you need searchable text
Photos of documents can be converted to searchable PDFs by running optical character recognition over each page and layering the recognised text underneath the image. That is what dedicated OCR tools do, and it produces a file you can search and copy from while still showing the original scan.
Related
Tools used in this guide
JPG to PDF
Combine photos or scans into one clean PDF document.
Compress image
Shrink photos and screenshots by trading quality for size, your call.
Resize image
Set exact pixel dimensions or scale by percentage.
Image to text (OCR)
Read the text out of a scan or screenshot and copy it as plain text.