How to scan a book to PDF with your iPhone, page by page

Your textbook weighs two pounds, the recipe book lives at your parents' house, and the spiral notebook from last semester is starting to fall apart. Here is how to scan a book with your iPhone and keep it as a PDF you can search: the setup, the page-by-page routine, and the fixes for the curved pages and shiny paper that make book scanning harder than scanning a letter.

Why scan a book to PDF on your phone

A scanned book does three jobs a paper copy cannot. You can search it for a word, you can carry a whole shelf on your phone, and you can stop opening a fragile copy that loses a page each time. Book scanning, as the Wikipedia article on book scanning describes it, turns physical books into images or electronic text, and software then aligns the pages and uses text recognition to make them searchable.

The cheapest professional method cuts off the binding and feeds loose sheets through a machine. That cut cannot be undone, so it is not for a book you want to keep. A phone scan leaves the book whole.

Two ways to shoot: one page or a two-page spread

You can capture one page per shot or both open pages in one shot. A two-page spread is faster, but the spine sits in the middle of the frame, the text near it curves, and each PDF page holds two book pages that read badly on a phone screen.

One page per shot takes twice the captures and gives you straight, full-width pages that you can zoom and search page by page. For a book you will read on the iPhone, pick one page per shot.

How to scan a book, step by step

The routine below works for a textbook, a workbook, a recipe book or a notebook. It uses a document scanner app on the iPhone; the capture flow is the same one Apple describes for scanning documents in Notes and Files.

1. Set up the light and the stand. Put the book on a dark table next to a window, with no lamp above you to throw the phone's shadow. Prop the phone on a stand or on a stack of books so it sits parallel to the page, or hold it with both elbows on the table.
2. Open the document camera. In MRS, tap the scan button in the middle of the tab bar. MRS uses Apple's document camera, which finds the page edges, captures the page automatically when it is steady and squares the page with a perspective fix.
3. Choose the color mode. The camera screen offers color, grayscale, black-and-white and photo modes. Pick black-and-white or grayscale for a text-only book and color for a recipe book with photos or a workbook with colored diagrams.
4. Scan page by page in one session. Turn the page, let the camera take the shot, turn again. Every page you scan before you tap Save goes into one PDF, so keep one chapter in one session.
5. Keep your fingers off the text. Hold the page down at the outer margin or the bottom corner, outside the printed area. A fingertip over a line hides that line from you and from text recognition.
6. Check each capture. Look at the thumbnail after every few pages. Retake a page with a blur, a shadow or a cut-off line now, while the book is open at that spot.
7. Save with the chapter name and file it. Rename the PDF in the library to "Biology 101 Ch 3 Cells" and move it into a folder such as Books › Biology 101. One document per chapter keeps each file short and makes a missed page easy to fix.

The part people get wrong: the spine and the shine

Curved pages near the spine are the most common problem. A thick book lying open bends each page down into the gutter, so the lines near the spine bow and darken. The document camera squares the page edges, but it does not flatten a curve, so you keep the page flat yourself: press the outer edge, or open the book less than flat and scan each side at its own angle.

Glossy paper is the second problem. Recipe books, art books and coated textbooks reflect the window as a white patch that wipes out the text under it. Turn the book a little until the patch leaves the page, and keep the flash off.

Phone scanning vs a flatbed scanner vs a book scanning service

Phone scanning, a flatbed scanner and a book scanning service trade speed, cost and the safety of the book in different ways. The phone keeps the binding whole and the book on your desk.

Which one to pick

Pick the phone for a book you own, use often and want on your iPhone this week. Pick a flatbed for a few loose pages, a fold-out map or a photo you want at full detail. Pick a service only when you have a box of books and do not mind losing the bindings.

The Wikipedia article on book scanning notes that a V-shaped cradle, which holds the book half open, reduces the curve at the gutter compared with a book lying flat. You get part of that effect at home by opening the book less than flat.

Tips for flat, readable pages

Flat pages come from your hands and your light more than from the camera. Small changes give clean text on every page.

• Press at the edges: put two fingers on the outer margin, one at the top and one at the bottom, and keep them outside the printed area.
• Use a dark background: a dark desk or a dark folder under the book gives the edge detection a clear border.
• Fill the frame with one page: move the phone so one page fills most of the frame and the opposite page is out of view.
• Weigh down a stiff book: lay a ruler or a strip of clear acrylic along the outer edge of a book that springs shut.
• Scan in daylight: soft light from one side leaves the gutter less dark than a lamp straight overhead.

For more on light, angles and color modes, read how to scan like a pro with your iPhone.

A rule for notebooks and workbooks

Notebooks and workbooks have their own rule: scan every page in order, blank pages included, if the page numbers matter. A workbook with your answers in pencil reads best in grayscale or color, because black-and-white mode can drop faint pencil lines.

Every page gets an invisible text layer as you scan, so the printed text in a workbook becomes searchable. For a title page, open the PDF in the MRS editor, add a blank page and type the book name, the edition and the date on it in one of 7 fonts.

How to check the scan of a book

A book scan is done when every page is there and you can find a passage in it. Check each chapter right after you save it, while the book is still on the desk.

• Page count: does the PDF have the same number of pages as the chapter in the book, with no double shots?
• Search: does a search for a word you know is in chapter 3 find chapter 3?
• Small print: can you read the footnotes and the page numbers at 100 % zoom?
• The gutter: are the lines nearest the spine straight enough to read without tilting the phone?
• The name: would you find "Ch 3 Cells" in a list of 40 files?

The search test

Text recognition, or OCR, converts images of printed text into machine-encoded text, as the Wikipedia article on optical character recognition explains. MRS runs it on the iPhone for every scanned page and detects the language by itself, so you do not pick one first.

Type a word from the middle of a chapter into the MRS library search, and the chapter that contains it shows up. Then open the PDF in the Files app or any PDF app and touch and hold a word; if it selects like text in an email, you can copy a quote into your notes. The guide on how to make a PDF searchable explains the text layer in more detail.

Common mistakes when you scan a book

Most failed book scans come from a few habits that are easy to change.

• Scanning two-page spreads: the spine curve lands in the middle of every page. Scan one page per shot instead.
• One giant session: a 300-page book in one PDF means one bad page sends you hunting through all 300. Save one chapter per document.
• Fingers on the text: a thumb over a line hides it from the search too. Hold the margins.
• Lamp straight overhead: the phone throws a shadow on the page. Use side light from a window.
• Skipping the check: a missing page is easy to retake today and hard to notice next month. Count pages per chapter.

Edge case: copyright and whose book it is

Scan books you own for your own use. The US Copyright Office fair use page describes fair use with four factors: the purpose of the use, the nature of the work, how much of it is used, and the effect on the market for the original. Read it there; this guide gives no legal advice, and rules differ by country.

A library book, a borrowed textbook or a book you plan to share is a different case from your own copy on your own phone. When in doubt, ask the library or the publisher.

Your book-scanning checklist and next steps

• Set up: dark desk, window light from the side, phone on a stand or a stack of books.
• Shoot: one page per shot, one chapter per session, fingers on the margins.
• Check: page count, a search for a known word, the lines near the spine at 100 % zoom.
• File: a Books folder, one subfolder per book, one PDF per chapter with a clear name.
• Keep: at about 46 KB per scanned page in MRS, a 300-page book is roughly 14 MB.

MRS keeps the scans on your iPhone with no account, and a deleted chapter stays in the Trash for 30 days. To send a chapter to a study partner, use the iOS share sheet; the guide on how to save a PDF on iPhone covers where the files can go. For loose papers around the books, see how to scan documents on iPhone and going paperless in one weekend, or download MRS for iPhone and start with chapter 1.