Nearly all software has a particular format that it automatically defaults to when creating a new document or file, but occasionally the chosen format does not seem to intuitively make sense. With that in mind, today’s SuperUser Q&A post has the answer to a curious reader’s question.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

The Question

SuperUser reader vico wants to know why scanners use PDF as the default save format:

A lot of scanning software has PDF set as the default format for newly created documents. Why is this?

As I understand it, scanned documents are pixel based pictures like those in cameras. I am unaware of any cameras that store pictures using the PDF format.

What does the PDF format bring to the table such that it is often set as the default?

Why do scanners use PDF as the default format?

The Answer

SuperUser contributor Atzmon has the answer for us:

There are several advantages to PDF files versus JPG or other graphic formats:

  • Self contained; you can OCR the text and keep the searchable text with the original bitmap (which is something most scanners can try to do automatically as part of the scan process)
  • Securable at the file level itself without using additional tools or relying on operating system specific features
  • Cannot be altered without leaving digital footprints
  • Can include metadata, which helps with filing and searching
  • Compressible with good control over the compression type and level
  • Supports multiple pages

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

Image Credit: npslibrarian (Flickr)

Akemi Iwaya
Akemi Iwaya has been part of the How-To Geek/LifeSavvy Media team since 2009. She has previously written under the pen name "Asian Angel" and was a Lifehacker intern before joining How-To Geek/LifeSavvy Media. She has been quoted as an authoritative source by ZDNet Worldwide.
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