Students & ApplicantsPDF

Combine phone photos into one PDF without a scanner app (and keep it under 10 MB)

SENULA COMPANY · 2026-09-19 · 5 min read

The size problem nobody warns you about

You photograph six pages of a signed lease, tap share, and the portal rejects the file. The limit is 10 MB. Your six photos add up to 28 MB. This happens because modern phone cameras default to 12–48 megapixels, producing individual images between 3 MB and 8 MB. A PDF container simply wraps those images without compressing them. Ten photos become a 40–60 MB file.

You do not need a scanner app subscription or a cloud service to fix this. Three shooting habits and one browser tool solve the problem entirely on your own device.

Three habits for clear document photos

1. Light from the side, not above. Place the document near a window with indirect daylight, or angle a desk lamp at roughly 45 degrees. Overhead lighting casts your phone's shadow onto the page.

2. Hold the camera parallel to the paper. Tilting the phone creates perspective distortion — the top edge looks wider than the bottom. Keep the phone flat above the center of the sheet so all four edges run parallel to the screen.

3. Use a dark, flat background. A white sheet on a dark wooden desk or a black mat creates strong contrast at the paper's edge. This makes alignment easy to verify and stops auto-crop from trimming margins.

These steps add no time once they become habit. The payoff is straight, evenly lit pages that need no post-processing.

Sort and name before you merge

Submitting pages out of order can delay a review or force a resubmission. Rename files with a simple scheme — page_01.jpg, page_02.jpg, page_03.jpg — so your operating system and the merging tool sort them correctly.

Before merging, review each image once. Remove duplicate captures and blurry test shots. Confirm portrait pages are vertical and landscape tables are rotated consistently. Verify the sequence matches what the recipient expects.

Why raw photos make oversized PDFs

A PDF does not compress images by itself. It packages whatever you give it.

Portal upload ceilings typically sit between 5 MB and 10 MB. Without compression, even three photos can exceed the limit.

Two settings during assembly bring the size down. First, cap the long edge of each image at 1,600–2,000 pixels. That is plenty for on-screen review and keeps printed text sharp at A4. Second, set JPEG quality between 75% and 85%, which strips invisible pixel data without blurring small type. Together, these reduce each page to 300–500 KB.

Worked example 1: Student submitting a handwritten assignment

A university student photographs 6 pages of a handwritten problem set with an iPhone (12 MP). Each photo is 4.2 MB. Raw total: 25.2 MB. The course portal allows one PDF, maximum 10 MB.

1. Add the six photos to Images → PDF. The tool sorts them by file name and applies EXIF rotation, so a page shot sideways displays correctly.
2. Set page size to A4, max long edge to 1,800 pixels, JPEG quality to 80%.
3. Download the PDF.

Each page drops from 4.2 MB to roughly 380 KB. Final PDF: about 2.3 MB. Every line of handwriting is still sharp, and the file sits comfortably under the 10 MB ceiling.

Worked example 2: Freelancer compiling receipts for reimbursement

A freelance consultant photographs 10 paper receipts on a dark desk using an Android phone (48 MP). Each photo: 6.1 MB. Raw total: 61 MB. The client's expense portal accepts one PDF, maximum 5 MB.

1. Add all 10 receipt images to the tool.
2. Set page size to "fit to image" — receipts are smaller than A4, so fitting avoids large white borders.
3. Set max long edge to 1,600 pixels, JPEG quality to 75%.
4. Drag one out-of-sequence receipt to its correct position. Remove an accidental duplicate.
5. Download the PDF.

Each receipt image drops to about 280 KB. Final 9-page PDF: roughly 2.5 MB. Well under the 5 MB limit.

Scanner apps and where your photos actually go

Some scanner apps send your images to a cloud server for processing. The app sharpens text, corrects perspective, and runs OCR — all on a remote machine. For a grocery list, this is harmless. For tax receipts showing purchase amounts, vendor names, and partial card numbers, it creates a copy of your financial data on someone else's infrastructure.

A browser-based tool that runs locally avoids this entirely. You can verify it with one test: load the page, disconnect from the internet, then run the conversion. If the PDF downloads while you are offline, nothing was sent.

Run the offline test once on a throwaway photo. After that, you can trust Images → PDF with real documents.

Settings quick reference

Start with 1,600 px and 80%. If the file is still too large, lower one setting at a time.

FAQ

Q: Will shrinking the long edge make small text unreadable?

A: At 1,600 pixels on the long edge, standard 10–12 pt printed text stays clear on screen and prints fine at A4. Below 1,000 pixels, fine print starts to blur.

Q: Can I mix portrait and landscape photos in one PDF?

A: Yes. EXIF rotation data is applied automatically, so a landscape receipt photographed sideways displays correctly without manual rotation.

Q: What if I need lossless quality?

A: Set JPEG quality to lossless. File sizes will be larger — expect 1–3 MB per page — but no compression artifacts will appear. This is useful for archival copies where every pixel matters.

The short version

Name files in order, shoot with the camera flat and the light angled, then run the photos through Images → PDF with the long edge capped and JPEG quality at 75–85%. Ten receipt photos that started at 61 MB turn into a 2.5 MB PDF any portal accepts — and none of those receipts touched a server along the way.