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Can't edit text in a scanned PDF?

If no line is highlighted when you open a PDF, it's probably a scan. Here's why it can't be edited and what you can still do.

Why can't I edit the text?

An ordinary PDF, such as one saved from a word processor, stores text as text. A PDF made by scanning paper or photographing a page is one big picture per page. It looks like text to you, but to a computer it's just pixels, so changing individual characters isn't possible. Turning those pixels back into text takes character recognition (OCR), which PdfMonster doesn't support yet.

How to tell it's a scan

With the Edit text tool on, no line is highlighted when you hover.
You can't select text by dragging in other PDF viewers.
When you zoom in, letters look pixelated and jagged.

Option 1. Get the original file (best)

If you have the original document from Word, Google Docs or a spreadsheet, fix it there and export a new PDF. The result is cleanest and has no font issues. If you don't have it, asking whoever made the document is often the quickest route.

Option 2. Cover and retype

A practical approach when only a spot or two needs to change.

Cover the text with a Rectangle (R) from the Shapes menu.
In the style bar, untick “None” for Fill and set the color to the paper color (usually white). Tick “None” for Line color to remove the outline.
Use the Text tool (T) to type the new text on top, and match its size and font to the surroundings.
Zoom in and check that the edges and colors line up.

Caution: this only covers the old text; it doesn't erase the original picture. Opening the file in another program and moving the cover away may reveal it, so don't use this to hide personal data or amounts. Altering a document so that it states something untrue is also prohibited (Terms of Use).

Option 3. Use an OCR tool elsewhere

To turn the scan into editable text you need software with OCR. Recognition can make mistakes, so compare the result with the original. If you save the converted document as a PDF again, that PDF can be edited in PdfMonster.

Tips for your next scan

About 300 dpi works well. Too low and letters blur; too high and the file gets huge.
Lay the paper flat and avoid shadows. On a phone scanning app, turn on automatic enhancement.
Scan black-and-white documents in black-and-white or grayscale to keep the size down.
If pages came out in the wrong order or orientation, fix them with Reorder, rotate and delete PDF pages.

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