How to edit a scanned PDF

When you scan or photograph a page, each page of the PDF is stored as a single image. To your eyes it is text; to the file it is a grid of pixels, just like a photo. There are no letters, words or fonts to select, which is why clicking the text does nothing and searching finds nothing.

To change that wording, the text first has to be recognized. Edit PDF can do it for you: it reads each line of the scan and replaces it with real text that you can edit like any other.

1. 1

   Turn on the scan option

   Go to Edit PDF and, before opening your file, tick Make scanned text editable. Under Language of the text, keep the Latin-script option for English, French, Spanish and similar languages, or choose Arabic (with French or English).

2. 2

   Open the scanned PDF

   Drop your file on the page or click choose a file. The document opens right away and a bar shows Scanning page 1 of 3… while the text is read. It takes a few seconds per page, and you can look around in the meantime.

3. 3

   Edit a line

   When the scan is done, double-click any line and type. Each line is now a text box placed over the original, with a matching font style, size and ink color, and the old pixels are covered in the color of the paper.

4. 4

   Download the result

   Click Download PDF. Your changes are part of the file, and the recognized lines can be selected, searched and copied.

Lines that can’t be read reliably, such as handwriting, stamps or cramped table cells, are left as they are in the scan. For those, choose Whiteout in the tool rail, drag a box over the words, then add new text with Text.

If you only need to search, select or copy the text and the page must stay exactly as scanned, use OCR PDF instead. It adds what it reads as an invisible text layer behind each page. The page looks the same, but you can now search it and extract its text with PDF to Text.

Pick the document languages under Document language (up to 3), leave Only add text that isn’t selectable yet ticked so lines the PDF already has as text are not added twice, and click Make PDF searchable.

Recognition runs in your browser in both tools. The OCR models (about 20 MB) download the first time, and your PDF stays on your device.

• Scan at a decent resolution. 300 DPI is a good target. Blurry phone photos and low-resolution faxes produce more mistakes.
• Fix the orientation first. Rotate sideways or upside-down pages with Rotate PDF before scanning the text.
• Use flat, evenly lit pages. On a phone photo with shadows, the covers behind edited lines follow one paper color and can show at the edges of a shadow.
• Expect weak results on handwriting, stamps, tables with heavy lines and very small print. Recognition is built for printed text.

Always check the recognized text before relying on it, especially names, numbers and dates.

Editing scanned lines is ideal for a few changes: a date, a name, an amount, a sentence. If you need to rewrite whole pages, it is usually faster to run OCR, copy the text out with PDF to Text, correct it, and create a fresh document with Text to PDF. For more on changing digital PDFs, see how to edit a PDF.