What is a seachable-PDF file?

A searchable PDF is simply a PDF file that contains useful search functionality. In fact, when you save a document as a PDF on your computer, it’ll typically be searchable as standard. You can usually use the Adobe Acrobat ‘Search’ function to highlight and source words and passages within the text.

However, when you use an external scanner or fax machine to copy a document and save that file as a PDF, it typically won’t be searchable - as it’s merely an image of the copied document, much like a photograph. To make this file searchable, you’ll need to convert it to a searchable PDF.

What does searchable-PDF stand for?

The PDF in “searchable-PDF” stands for Portable Document Format. PDFs are file formats that protect and retain the formatting of an original document. This can be useful when sending documents to others that don’t have the same software as you.

For example, if you convert a file from Word to PDF it retains the formatting of the original programme, regardless of whether the people you send it to have the same version of Word. Searchable-PDFs are simply ‘searchable’ versions of these documents.

History of the searchable-PDF file.

The basic function of a searchable-PDF is to make image-based PDFs text-searchable. To do this, OCR (Optimal Character Recognition) is applied to the document. This recognition tool is able to read handwritten text in a variety of fonts and digitise it for use on a computer. OCR technology dates back to the 1970s.

PDFs themselves were created in 1992 by Adobe Inc. They fix the layout format of a file to preserve the look and style of the content during transfer to other users. The searchable function has existed for as long as PDFs have been on the market.

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What are searchable-PDF files used for?

The primary use of searchable-PDFs is to make the text in image-based PDFs searchable using Adobe Acrobat’s PDF Search tool.

Searching image documents.

In order to make the text in faxed or scanned documents searchable in Adobe Acrobat’s native PDF reader, OCR technology must be applied to the saved file.

The optical recognition tool reads the physical text and digitises it - making it searchable in the same way text typed directly into a document is.

Searchable-PDFs are the result of this process.

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Advantages of searchable-PDF files.

The searchable-PDF file format allows you to navigate image-PDFs in order to:

  • Source sentences
  • Sift through passages of text
  • Highlight certain words or phrases.

…without having to trawl through the entire document manually.

It is therefore capable of saving you a great deal of time and effort, especially if you frequently need to scan documents.

How to open a searchable-PDF file.

Opening a searchable-PDF is as simple as opening any PDF file.

You’ll need Adobe Acrobat install on your device first. Afterwards, just double-click or tap the file you want to open and it should open in your Acrobat Reader, displaying as a searchable-PDF.

How to create and edit a searchable-PDF file.

To get started, you’ll need an existing image-based PDF file. This might be a visual copy of a physical document you’ve scanned, which is now stored on your computer.

To convert the image-based PDF into one that is searchable, you’ll need the latest version of Adobe Acrobat. Open your document in Acrobat to get started.

Then, follow the steps below:

  1. Click Tools > Text Recognition > In this File
  2. Select All Pages in the popup box or the range of pages you wish to make searchable
  3. OCR will then be applied to the document.

You can select multiple documents at once to convert into a searchable PDF, by choosing the Multiple Files option rather than In This File.

If further documentation needs to be combined, you can add pages to your PDF or even merge PDFs together.

Editing a searchable-PDF

To edit a searchable-PDF, you’ll need a PDF editing tool - ideally Adobe Acrobat. Simply select the Edit PDF tool to make your changes.

Learn more about similar file types to searchable-PDF.

PDF/VT

The printing standard for variable data. Find out more about this file today.

PDF/A

Discover how and where PDF/An is used and get to know this format with our guide.

PDF/E

You might encounter PDF/E if you work in engineering or technology - learn more about it here.

PAdES

PAdES are especially useful if you need to add signatures to your documents. Read our guide for more info.

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Searchable-PDF FAQs.

What is the difference between PDF and searchable PDF?

A searchable-PDF is usually an image-based PDF - often a scanned copy of a physical document - that has had text recognition added to it to allow a user to search and source elements of the content within it. Most PDFs do however include the same search function as standard.

Why are some PDFs not searchable?

If a PDF is image-based, such as a scanned or faxed copy of a physical document, the PDF will not be searchable as it is effectively an image copy of the original content. As a result, its written content isn’t recognised as text. However, converting the file into a searchable format will allow the text to be read digitally.

How do I turn paper documents into searchable PDFs?

To turn a physical document into a PDF with text recognition function, you’ll first need to scan the document into your computer and save as a PDF. Once you’ve done that, open your saved PDF file in Adobe Acrobat. Then you can convert the file into a readable format by clicking through Tools > Text Recognition > In This File.

How do I run text recognition in Adobe?

You can run OCR technology in Adobe Acrobat with ease. Just use the Text Recognition tool to analyse an image-based document.

Why can’t I recognise text in my PDF?

You might not be able to recognise text in your PDF if your document is image-based. An image-based PDF is much like a photograph or image copy of a physical document. Alternatively, it could be that the original data is corrupted for some reason if your file is not image-based.

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