How to Scan Documents With Your Phone and Turn Them Into a Clean PDF

Get scanner-quality PDFs from phone photos: lighting, angles, built-in scanner apps, combining pages, fixing rotation and keeping file size down.

NewKitApp19 octobre 2026 9 min de lecture

Nos guides existent en anglais et en indonésien. Les articles ci-dessous s'ouvrent en anglais.

Most people don't own a scanner any more, and they don't need one. The camera in a mid-range phone captures more detail than an office flatbed did ten years ago. What separates a crisp, readable PDF from a blurry, shadowed mess isn't the hardware. It's light, angle, a couple of settings and what you do with the photos afterwards.

This guide covers the whole process: preparing the page, taking the photo, using the scanner apps already on your phone, combining photos into one PDF, fixing rotation and order, and getting the file small enough to send.

Before you shoot: set up the page

Five minutes of preparation saves twenty of editing.

Flatten the paper. Creases and curls cast shadows and bend lines of text. Press folded letters under a heavy book for a minute. For bound documents, press the spine gently so the pages lie as flat as possible.

Use a dark, plain background. A dark table or a sheet of dark card behind white paper gives strong contrast at the edges. Scanner apps use that contrast to detect the page and crop it automatically. Avoid patterned tablecloths and wood grain.

Find good light. Daylight from a window is ideal: bright, even and colour-neutral. Stand so the window is to your side, not behind you, or you'll shadow the page. At night, use two lamps from opposite sides to cancel shadows. Avoid the phone's flash, which causes a bright hotspot and glare on glossy paper.

Clean the lens. Phone lenses collect fingerprints. A smudged lens gives a hazy, low-contrast image. Wipe it with a soft cloth.

Taking the photo

Hold the phone parallel to the page. The most common mistake is shooting at an angle, which turns rectangles into trapezoids and makes the far end of the text smaller and blurrier. Hold the phone directly above the page, screen parallel to the paper. Many camera apps show a level indicator (on iPhone, turn on Grid in Settings, Camera, and a crosshair appears when the phone is flat).

Fill the frame. Get close enough that the page fills most of the screen with a little margin around it. More pixels on the page means sharper text.

Tap to focus on the text. Let the camera focus and expose for the page, not the background.

Hold still. Brace your elbows on the table, or take two shots and keep the sharper one. In low light, the phone uses a slower shutter, and any movement blurs fine text.

Turn off "live" or motion photos for documents. They create larger files and sometimes save a frame that isn't the sharpest.

Use the scanner already on your phone

You may not need a separate app. Both major phone platforms include a document scanner that crops, straightens and enhances automatically.

iPhone and iPad

Notes app: create a note, tap the camera icon, choose Scan Documents. Hold the phone over each page; it captures automatically when the page is steady. Tap Save, then share the scan as a PDF.
Files app: in Files, tap the three dots at the top, then Scan Documents. The PDF saves straight into the folder you're in.

Android

Google Drive: tap the + button, then Scan. It detects edges, lets you crop and choose a colour mode, and saves a PDF to Drive. (The file goes to Google's servers, since it's saved in Drive.)
Google Lens / Camera: many Android camera apps detect documents and offer a "scan" button.
Samsung, Xiaomi and others include scanner modes in their camera apps.

These built-in scanners do perspective correction (turning the trapezoid back into a rectangle) and contrast enhancement, which is exactly what makes a phone photo look like a scan.

When you already have photos

Sometimes you've already taken ordinary photos, or someone sends you pictures of a document. You can still turn them into a clean PDF.

JPG to PDF and Images to PDF take photos in JPG, PNG, WEBP, HEIC-converted JPG and other formats and place them one per page:

Open the tool and select all the photos at once.
Check the order. Photos named by the time they were taken usually arrive in shooting order. Fix any out-of-place ones with the arrows.
Choose A4 (or Letter in North America) so every page has a standard printable size, regardless of the photo's shape.
Leave orientation on Auto. Landscape photos get landscape pages.
Set a small margin, about 5 to 10 mm, if the PDF will be printed.
Click Create PDF and download.

If your photos include a lot of desk around the page, crop them in your phone's photo editor first. It takes a few seconds per photo and makes a big difference to how professional the result looks.

HEIC photos from iPhones

iPhones save photos as HEIC by default to save space. Not every browser can read HEIC. Either change the setting (Settings, Camera, Formats, Most Compatible) before shooting documents, or share the photos and choose JPG when the share sheet offers it, or export them from Photos as JPG.

Fix rotation and page order

Phones decide which way is up based on how you hold them. When you shoot straight down at a table, the sensor can't always tell, and pages end up sideways or upside down.

All pages turned the same way? Use Rotate PDF and rotate them all at once.
Only some pages turned? In Rotate PDF, click those thumbnails to select them and rotate only those.
Pages in the wrong order or a page you don't want? Organize PDF lets you drag pages around, rotate individual pages and delete blurry shots.

Colour, grayscale or black and white

Phone photos are in colour, which is right for documents with stamps, signatures in blue ink, highlighted text or photos. For plain printed text, colour adds file size and nothing else.

Grayscale PDF converts a colour PDF to shades of gray. For text documents it reduces size noticeably and often improves readability by removing the yellowish tint of indoor lighting. If you plan to print the document on an office printer, grayscale also avoids colour printing charges.

Keep colour for:

ID cards and passports (colour is part of verification)
documents with official stamps or seals
signatures where the ink colour shows it's an original
receipts with coloured highlights the recipient needs

Keep the file size reasonable

A phone photo weighs 2 to 8 MB. Ten pages can easily reach 50 MB, which is too large for most email and every upload portal.

Run the PDF through Compress PDF on Balanced. Photos of paper documents compress extremely well because most of the page is plain white. Expect 80 to 95 percent savings. A 40 MB ten-page scan often comes out under 3 MB with no visible difference at normal zoom.

If you need it even smaller, try Strong, and check that small print, signatures and numbers are still readable at 100 percent zoom. For purely text documents where nobody needs to select the text (a scan has no selectable text anyway), the Maximum compression option gives the smallest result.

Making scans searchable

Photos and scans contain pictures of text, not text. You can't search them or copy from them. If you need that, run the PDF through OCR software, which recognises the letters and adds an invisible text layer:

iPhone: Live Text lets you select text in photos, and the Notes scanner makes text selectable in some cases.
Google Drive: right-click a PDF, Open with, Google Docs. It runs OCR and creates an editable document.
Adobe Acrobat (paid) and ABBYY FineReader (paid) produce high-quality searchable PDFs.
Microsoft OneNote can copy text from a picture.

OCR accuracy depends on the scan quality, so everything earlier in this guide (light, flatness, angle, focus) pays off again here.

Special cases

Receipts

Thermal-paper receipts fade over time and curl. Flatten them, shoot them against a dark background in good light, and keep colour if any part is highlighted. Many expense systems want one receipt per page; use Split PDF with "Every page" if you scanned several into one file.

ID cards and passports

Shoot on a dark background so the card's edges stand out. Avoid glare on laminated surfaces by tilting the light source, not the phone. Many forms want the front and back on the same page; if so, photograph both sides and combine them into one image with your phone's photo collage feature before making the PDF, or accept two pages if the form allows it.

Books and bound documents

The curve near the spine distorts text. Press the page flat with your hand outside the frame, or use a sheet of clean glass over the page (watch for reflections). Some scanner apps include a "book" mode that flattens the curve in software.

Multi-page contracts

Scan every page, including blank backs if they're part of the original, so the page count matches. Then remove truly blank pages only if the recipient doesn't need them.

Whiteboards

Whiteboard photos benefit from high-contrast processing. Scanner apps often have a whiteboard mode that removes glare and boosts marker colours.

Common problems and fixes

The text looks soft or blurry. The phone moved, or it focused on the background. Tap on the text to focus, brace your elbows and shoot again. In dim light, add a lamp rather than relying on the night mode, which smooths fine detail.

There's a dark shadow across the page. Your body or the phone is blocking the light. Move so the light comes from the side, or raise the phone a little and zoom in slightly.

The page edges are curved. The paper isn't flat, or you shot at an angle. Flatten the paper and hold the phone parallel to it. Built-in scanner apps also correct some curvature.

White looks grey or yellow. Indoor light is warm and dim. Use daylight, or convert to grayscale and let the scanner app's "enhance" or "document" filter brighten the background.

The PDF is huge. Phone photos are big. Compress on Balanced; documents photographed on white paper usually shrink by 90 percent.

Glare on glossy paper or ID cards. Move the light source, not the phone, until the reflection leaves the card. Turning off overhead lights and using a single side lamp often helps.

A quick routine

Flatten the pages and set them on a dark, plain surface near a window.
Shoot from directly above with a clean lens, or use your phone's built-in document scanner.
Crop out the background if you used the normal camera.
Combine the photos into one PDF with JPG to PDF, using A4 or Letter.
Rotate any sideways pages and remove bad shots.
Convert to grayscale for text-only documents.
Compress on Balanced.
Open the final PDF and read one page at 100 percent zoom before sending.

How much resolution do you need?

Scanner settings talk about DPI (dots per inch). A phone doesn't, but you can think about it the same way. An A4 page is about 8.3 by 11.7 inches. For comfortable reading on screen, 150 DPI is plenty: about 1250 by 1750 pixels. For printing and OCR, 300 DPI: about 2500 by 3500 pixels. Any modern phone camera captures more than that when the page fills the frame, so resolution is rarely the limit. Sharpness, light and angle are.

Privacy

Scans are often the most sensitive documents people handle: IDs, bank letters, medical forms. Many scanner apps upload your pages to their servers to process them, and some keep them in a cloud account by default. Check the app's privacy settings. The browser tools on NewKitApp, including JPG to PDF, Rotate, Grayscale and Compress, process everything on your device, so the photos and the finished PDF never leave your phone or computer.

Summary

Phone scanning comes down to good light, a flat page, a parallel camera and a little post-processing. Use your phone's built-in document scanner when you can; otherwise take careful photos, crop them, combine them into an A4 or Letter PDF, fix rotation, switch to grayscale for plain text, and compress before you send. The result looks and behaves like a proper scan, at a fraction of the effort a trip to a copy shop would cost.