Organize guide
Merge Scanned Pages into One PDF on a Phone
Updated
Short answer: Open Merge PDF in your phone's browser, add your scanned PDFs (or use JPG to PDF for photos), drag them into order and download one file.
Phone scanners often save each scan as a separate file, while forms and portals want every page in one PDF. You don't need an app for this: ToPDF's merge and image tools run in mobile Safari and Chrome, on the phone itself.
Step by step
Step 1: Scan each page. On iPhone, the Notes and Files apps can scan documents; on Android, Google Drive's scan button does the same. Save the scans to Files or Downloads.
Step 2: If your scans are PDFs, open Merge PDF and tap the drop area to pick them.
Open Merge PDF(runs on your device)Step 3: If they're photos (JPG or PNG), use JPG to PDF instead and choose A4 or Letter so every page is a standard size.
Open JPG to PDF(runs on your device)Step 4: Drag the files into the right order, then merge and download.
Step 5: To turn a page the right way up or remove a bad scan, open the result in Organize PDF.
Open Organize PDF(runs on your device)
Why this works, and what to watch for
All three tools are browser tools: the page loads once, then the work happens in your phone's browser. The scans aren't uploaded, which matters when they're ID documents, payslips or medical forms. They're also free and unlimited, because there's no server cost to ration. Once the page has loaded, they even work in airplane mode.
Merging copies each page into the new file as it is, so there's no re-compression and no loss of quality; the merged file is roughly the sum of its parts. If that's too large to email or upload, run it through Compress PDF afterwards. Scans usually shrink a lot, because they're nothing but images.
With photos, the page size option matters. Fit image makes each page exactly the shape of its photo, which looks uneven when shots differ slightly and can confuse portals that expect A4 or Letter. Choosing a paper size scales each image to fit a standard page and turns the page landscape for landscape shots.
Phones are capable but have less memory than a laptop. Dozens of full-resolution photos at once can make a browser tab reload. If that happens, combine them in batches of ten or so, then merge the batches.
Finding the file afterwards: on iPhone, downloads go to Files → Downloads by default; on Android, to the Downloads folder, with a notification when they finish.