How to Scan Documents with Your Phone and Turn Them into a PDF
A step-by-step workflow to scan paper documents with an iPhone or Android phone, get clean results, combine pages into one PDF, make it searchable and keep the file small.
You no longer need a scanner for most documents. A phone camera, a bit of light and the right workflow produce scans good enough for tax offices, insurance claims and job applications. Here is the routine we recommend.
Step 1: use the built-in scanner if you have one
Both major phone platforms have scanning built in, and it is better than taking a normal photo because it corrects perspective, crops the edges and increases contrast:
- iPhone: open the Notes app, create a note, tap the camera icon and choose “Scan Documents”. The Files app has the same function under the three-dot menu. Scans are saved as PDF.
- Android: Google Drive has a Scan button (the camera icon or the + button, then Scan). Many phone makers also include document mode in the camera app.
If you only have ordinary photos, that is fine too: the next steps work with JPGs.
Step 2: get the photo right
- Light: daylight near a window is best. Avoid the flash and the shadow of your own phone.
- Background: place white paper on a dark table so the edges are easy to detect.
- Angle: hold the phone directly above and parallel to the page.
- Sharpness: tap to focus and wait a moment. Blurry scans are the number one reason documents are rejected.
- One page per shot. Two pages in one picture are hard to read and to print.
Step 3: combine pages into one PDF
Most portals want a single PDF rather than five separate images. Send the photos to your computer or open the tool on your phone, then use JPG to PDF: choose all pages, put them in order, choose A4 or Letter and convert. Photos taken in portrait mode are rotated correctly automatically.
If you already have several PDFs, for example a scanned form and a certificate, join them with Merge PDF.
Step 4: keep the file small
Phone photos are large. Ten full-resolution pages can easily exceed the 5 or 10 MB limit of many upload forms. Before creating the PDF, run the photos through Compress Image with a maximum width of around 1600 to 2000 pixels. Text stays perfectly readable and the PDF usually shrinks by 70 to 90 percent.
Step 5: make the text usable
A scan is a picture: you cannot search it or copy text from it. If you need the text, for example to fill a form or quote a paragraph, run the PDF through OCR. For best results, use the right language setting and the clearest scan you have.
Step 6: name and store it properly
Name the file so you can find it in five years: 2026-10-12-rental-contract-signed.pdf. Store important scans in at least two places, for example your computer and an encrypted cloud folder. Delete the original photos from your phone gallery if they contain ID numbers or bank details, because galleries are often synced and shared in ways people forget.
When you still need a real scanner
- Large batches of pages, where a document feeder saves time.
- Photos and artwork that need accurate color.
- Documents where an official certified copy is required.
Our take
The phone is now the best scanner most people own. The difference between a scan that gets accepted and one that gets rejected is almost always light and sharpness, not the app. Take one careful photo per page in daylight, combine them into one PDF, shrink it before uploading, and you will never queue at a copy shop again.