You know the situation. The professor asks for "the assignment as a single PDF," but what you actually have is six loose phone photos: pages one through six of your notebook. Or you've collected four receipts, a signed contract page, and a headshot that all need to go to HR as one attachment. Sending six separate images looks unprofessional, and most upload forms will only accept a single file anyway.
The fix is to combine the photos into one multi-page PDF. It's a skill that looks trivial once you know it, yet I still watch people struggle through it. Here's how to do it on a phone and on a computer, plus the three-step in-browser method I use when I want it done in ten seconds without installing anything.
Why a PDF beats sending loose photos
A PDF is a fixed-layout document: every recipient sees the same page size, order, and margins, regardless of their device. Send loose JPEGs and the receiver has to download each one, view them in some random order, and print them one at a time. A single PDF prints, emails, and uploads cleanly. It also compresses the images sensibly, so a 20-page notebook PDF is usually a few megabytes rather than twenty photo-sized files.
Doing it on your phone
If the photos are on your phone, you have two built-in routes. On iPhone, open the Photos app, select all the images you want in the PDF, tap the share button, and choose Print. On the print preview screen, pinch-zoom out on the preview — iOS silently converts the selection into a PDF, which you can then save to Files or share. On Android, the equivalent is usually in your gallery's "Create" or "Print to PDF" option, or via Google Drive's scan feature. These work, but they're fiddly, and you can't easily reorder pages or set margins.
Doing it on a computer
On a Mac, select the images in Finder, right-click, and choose Open With → Preview, then use View → Contact Sheet to arrange and File → Export as PDF. On Windows there's no single built-in one-click button, which is exactly why people reach for a tool. Either way, you're fighting the OS rather than using it.
The three-step in-browser method I actually use
For anything more than two photos, I use our images-to-PDF converter. It runs entirely in the browser, so the photos never upload anywhere — which matters if you're merging scans of ID documents or signed contracts. The flow is:
- Drag in your photos. Drop every JPG, PNG or WebP onto the page. They appear as thumbnails in the order you added them.
- Arrange and configure. Drag the thumbnails into the correct page order. Pick paper size (A4 or Letter), orientation, and a margin. Tick "fit to width" if you want each photo to fill the page edge-to-edge.
- Export. Hit download and you get one PDF, one image per page, ready to upload or email.
A4 vs Letter: which paper size?
This trips people up. A4 (210 × 297 mm) is the standard everywhere except North America. Letter (8.5 × 11 in) is the standard in the US and Canada. Choose based on who will print or read it:
| Audience | Paper size | Why |
|---|---|---|
| US / Canada schools & offices | Letter | The printer paper in the tray |
| Rest of the world | A4 | The default everywhere else |
| Phone-only viewing | Either; A4 is fine | Screen reading doesn't care much |
| Portfolio / gallery prints | Match the lab's spec | Often 4×6 or custom |
If you're unsure, A4 is the safer default for an international audience and Letter for a US one. Getting this wrong isn't catastrophic — the PDF still opens — but a Letter document printed on A4 paper leaves an awkward border, and vice versa.
Ordering and margins: the details that make it look clean
A merged PDF looks amateurish for two avoidable reasons. First, wrong page order — I once submitted a lab report where the conclusion came before the method because I'd selected photos in the wrong order. Always drag the thumbnails into a deliberate sequence and scroll through the live first-page preview before exporting.
Second, missing margins. A photo bleeding straight to the paper edge looks cramped and can get cut off by printers that can't print to the very edge. Leave a modest margin (around 10–20 mm, or use the tool's default) so the page looks like a document, not a screenshot dump. If the photo is portrait and the page is portrait, "fit to width" leaves a comfortable top/bottom margin automatically.
Real scenes where this comes up
- Homework: photograph each notebook page, merge into one PDF, upload to the LMS. Number the pages as you go so the order stays sane.
- Resumes / job applications: a headshot plus a portfolio spread as a single attachment, rather than two files the recruiter has to juggle.
- Receipts and expenses: merge four receipts into one PDF for your accountant or expense claim.
- Signed documents: after signing on paper, photograph each page and merge them — just keep the photos legible (see our scanning tips below).
If you ever need to go the other way — pull images back out of a PDF someone sent you — the PDF to JPG tool extracts every page (or selected pages) as an image, at a DPI you choose.
Turn a folder of photos into one clean, ordered PDF — no upload, no account, works offline.
Open the images-to-PDF converterFrequently asked questions
How many photos can I merge into one PDF?
As many as you like. Each image becomes one PDF page. A 30-photo assignment merge is no problem; the only practical limit is the final file size, which for normal photos stays under 20 MB even for a couple dozen pages.
Can I reorder the pages after adding photos?
Yes. The thumbnails are drag-to-sort: grab any image and drop it into the position you want. Do this before exporting, and glance at the first-page preview to confirm the order is correct.
Should I choose portrait or landscape?
Match the photos. Notebook pages and receipts are portrait; wide diagrams or landscape photographs are landscape. You can't mix orientations per page in a simple merge, so if most of your shots are portrait, choose portrait.
Will the PDF quality be good enough to print?
For normal homework and documents, yes — phone photos at camera resolution print fine on A4/Letter. For gallery-quality prints you'd want the original high-resolution files rather than merged phone snapshots.
Is it safe to merge scans of ID or signed papers here?
Yes, because the merge happens locally in your browser. The images are never uploaded to a server; you can disconnect the network after the page loads and it still builds the PDF. That's the whole point of a browser-based tool.
