How do I improve the accuracy of text recognition in my scanned PDF?

Scan your document at a higher resolution, ideally 300 dpi, for clearer images. Select the correct language for the text in your document before starting OCR. Ensure the scanned image is clear and free from smudges or poor lighting.

What is the difference between a scanned PDF and a regular PDF in terms of text interaction?

Feature Scanned PDF (before OCR) Regular PDF (or scanned PDF after OCR). Text Search No, text is part of an image. Yes, text is selectable and searchable. Text Copying No, you cannot select or copy text. Yes, you can select and copy text. File Size Often larger if high-resolution image. Can be optimized; text layer is small. Editing Text Cannot directly edit text. Can edit text (if font is embedded and editable).

Recognize Scanned Text in Adobe Acrobat — How-to & AI prompts

AI prompts

2 ways to ask · copy any one

AExecute — “help me do it”Run OCR on the scanned deposition transcript from [date=June 8] so key passages can be…+

Run OCR on the scanned deposition transcript from [date=June 8] so key passages can be searched: recognize text across all pages, verify text layer accuracy, and export a searchable PDF to our matter folder by close of business.

when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed.

BImprove — “do it better”Before distributing the transcript, make it searchable and reliable for citations: run OCR on…+

Before distributing the transcript, make it searchable and reliable for citations: run OCR on the [date=June 8] scan, correct obvious recognition errors in speaker names and timestamps, embed the searchable text layer, and export both a searchable PDF and a plain text file to the matter folder so counsel can search and copy quotations without re-OCRing.

when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed.

How to do it

the tool · the steps · what to avoid

1
Open the scanned PDF file in Adobe Acrobat.
2
Go to the Tools menu.
3
Select Scan & OCR from the tools list.
4
Click Recognize Text and choose In This File.
5
In the settings panel, ensure PDF Output Style is set to Searchable Image.
6
Click Recognize to start the OCR process.
7
Save the PDF after OCR is complete.
Best practiceFor best OCR accuracy, scan your documents at 300 dpi and ensure the images are clear before running OCR.

In the appWith the API

After OCR completes, you can search, copy, and highlight text in your previously scanned PDF.

This runs in the Acrobat app - there is no separate API for this task.

Glossary

words on this page

OCROCR stands for Optical Character Recognition. It is technology that turns images of text into real text you can search and copy.ExampleAfter scanning a paper invoice, OCR allows you to copy the vendor's name from the image.

Searchable LayerA hidden layer of text added to an image-based PDF, allowing you to search for words within the document.ExampleThe hidden searchable layer in the scanned contract allowed us to find specific clauses.

DPIDPI means dots per inch, and it tells you how clear an image is when it is scanned.ExampleA scanned photo saved at 300 DPI will usually contain more detail than the same photo at 72 DPI.

Who does this

3 roles

ArchivistResearch LibrarianRecords Manager

FAQ

about this task

Scan your document at a higher resolution, ideally 300 dpi, for clearer images.
Select the correct language for the text in your document before starting OCR.
Ensure the scanned image is clear and free from smudges or poor lighting.

A searchable text layer is an invisible layer of actual text placed over the image of a scanned document. It matters because it allows you to search for words within the document, copy text, and index the document for easier organization and retrieval. Without it, a scanned document is just a picture, and you cannot interact with the text.

Acrobat shows this message because the page you are trying to process already has real text, not just an image of text. The 'Recognize Text' feature is designed only for image-based pages. If your document already has text, you do not need to run OCR on it, as the text is already searchable.

Yes, you can automate text recognition for many scanned documents using the Adobe PDF Services API. This allows developers to integrate the 'OCR PDF' operation into their own applications or workflows. It's useful for converting large batches of image-only PDFs into searchable documents for archiving or data extraction.

Feature	Scanned PDF (before OCR)	Regular PDF (or scanned PDF after OCR)
Text Search	No, text is part of an image.	Yes, text is selectable and searchable.
Text Copying	No, you cannot select or copy text.	Yes, you can select and copy text.
File Size	Often larger if high-resolution image.	Can be optimized; text layer is small.
Editing Text	Cannot directly edit text.	Can edit text (if font is embedded and editable).

Recognize Scanned Text

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help

When it fails