How to scan documents to PDF with your phone

You no longer need a scanner to send a signed form or a stack of receipts as a PDF. A phone camera can do the job well, provided you avoid a few common mistakes. Here is how to get clear, readable scans that aren’t enormous files.

Use a document scanner, not the camera app

Phones have built-in document scanning that does far more than take a photo. It finds the edges of the page, straightens it, removes the background and boosts contrast so text is crisp.

• iPhone and iPad: open the Notes app, create a note, tap the camera icon and choose Scan Documents. The Files app offers the same option from its menu.
• Android: Google Drive has a Scan button (the camera icon or the “+” menu). Many manufacturers also include a scanner in their camera app.

These apps can usually save directly as PDF. If you already have ordinary photos, JPG to PDF combines them into one document.

Five habits for better scans

1. Light it evenly. Daylight from a window is ideal. Avoid overhead lights that cast the shadow of your phone across the page.
2. Lay the page flat on a dark, plain surface so the edges are easy to detect.
3. Hold the phone parallel to the page, directly above it, to avoid a trapezium-shaped result.
4. Fill the frame with the page, but leave a small border so nothing is cut off.
5. Check each page before moving on, especially small print and signatures.

JPG or PNG?

For photographed paper, JPG is the right format: it handles the subtle shading of real paper well and produces much smaller files. PNG suits screenshots and computer graphics with flat colours and sharp edges. Mixing formats in one PDF is fine.

iPhones save photos as HEIC by default, which many browsers and websites can’t read. If an upload fails, change Settings › Camera › Formats to “Most Compatible”, or use the Share sheet to send the photo as JPG.

Putting pages in order

With several photos, order matters. Rename files with numbers if you can, then arrange them before creating the PDF. If a page ends up sideways, fix it with Rotate PDF; to reorder or remove pages afterwards, use Organise PDF.

Keeping the file size down

Scans from a document-scanner app are usually modest in size. Ordinary photos aren’t: twenty full-resolution phone photos can make a 60 MB PDF. Run the finished document through Compress PDF; scanned pages typically shrink by 70% or more with no visible loss on screen. If colour doesn’t matter, greyscale saves further space and prints more clearly.

Making scans searchable

A scan is a picture of text, so you can’t search it or copy from it. Optical character recognition (OCR) adds an invisible text layer. Some phone scanner apps do this automatically. Browser-based OCR is on our roadmap; until then, check whether your scanning app offers a “recognise text” option.

Privacy when scanning

Photos can contain location data and other details. Scanner apps generally strip these from the PDF, but ordinary photos keep them when embedded as they are. If that matters, turn off location tagging for the camera, or remove location data before converting. Scans of identity documents and bank statements are sensitive: process them on your own device where possible, and don’t leave copies in shared folders.