Why Use PDF over HTML


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As a web professional and an avocate for inclusive design (web accessibility) I have often wondered why organisations are so obsessed with using PDF documents on web sites as opposed to HTML based documents.

After all PDF documents don’t do accessibility as well as HTML pages do.

Given the ease of use of most modern CMS you would consider web page creation and editing would be as easy as authoring a word document.

Now I have a good idea why my clients use PDFs over HTML, especially government agencies, but I don’t have the community wide picture.

So I asked Twitter – “Why do you use PDF over HTML?”

I got a bit of a response.  Now this survey and its (200) responses aren’t that scientific, they are multiple tiered and are as expected, full of statistical analysis holes. Still the results do give us a glimpse as to why people use PDFs.

Now there is no primary reason as to why, but more a mesh of several supporting rationals.  They are in order of preference:

  1. Preserving the Print Format

    The requirement to have the onscreen visuals appear the same as the print version was clearly the leading reason. Out stripping others by two to one.

    This is really understandable when you are dealing with documents having a complex print layout. It seems CSS print styles just don’t cut it. To the point that sometimes having a different style layout for print, for a web page, can be a bit of negative user experience (however that’s another topic).

    Documents that have been through a visual design process of a print production team seem prone to this requirement. Yes the content is the primary focus here,  but sometimes the way it’s presented can be just as important in communicating the message.

  2. Encapsulated Format

    Being able to save and transfer a document across platforms was important as well.

    People are looking for a medium that doesn’t require complex software, that will maintain the layout, images, typeface and all the content as one encapsulated package.

    Try saving a web page for use later, it just fails in so many ways, and a MS-Word document – well that needs MS-Office for the most part.

    PDF is the only one left standing as an encapsulated package, it’s also cheap to read and produce as well.  Issue is it’s not that portable in reality – take the issues displaying or saving a PDF viewed on the web using a mobile device.

  3. Easier to Publish

    Easy of publication is another core reason. To creative a PDF is often just a simple process of saving a document.

    This is easy and within an existing business workflow.  So it’s understandable that it appeals to the vast majority of people.

    To publish it to a web site you just create the link in the CMS, and upload the document. Set and forget, no need to worry about the layout working or not.

    Contrast this with the list of issues using a CMS editor to create a web page.

    You usually create the document in MS-Word and have to cut and paste it into the CMS editor, this causes layout issues. Or you have to use some weird keyboard/process gymnastics to get the layout reproduced right or worse have all the formatting disappear and have to reapply the lot.

    Then you have to put the images in separately, scaled down for the web, and allow for those accessibility tags.  After all this there still maybe layout issues with the page design.    It’s just a nightmare.

    Clearly the web publishing process has a long way to go.   Maybe this is an area some of my fellow UX colleagues could look into?

  4. Existing Hardcopy Documents

    Duplication of existing hardcopy documents is also another core reason.

    When you have an existing hardcopy document, you really are only duplicating the distribution and availability of the document to a web medium.  You are just presenting the document to a wider audience that those that can collect it from your offices.

    The use of PDF with its layout preservation and encapsulated package is the perfect solution for hardcopy duplication.

    In this case people also stated that they tended to only used PDF for duplication exisiting hardcopy documents.

  5. Other Reasons

    The following are minor reasons people stated for use of PDF documents over web pages.

    • Duplicate HTML Content

      A low percentage of people indicated they presented everything as web pages, but also allowed for user driven server side generation of PDF documents as required. Or they just  duplicated all the static PDF information available as web pages. Use of both formats was equally weighted in this case.

    • Providing More Detail

      Others, using the semantic structure of the web, presented summary information on topics at the high level of a site as web pages moving down to specific summaries on mid level web pages and PDFs as the final low level detailed pages.  This is a very typical government model of information communication.

      I suspect while  this may not be prefect, it harks back to having a secondary reasoning for the ease of publication of the detailed information.

    • Interactive Forms

      Despite Adobe pushing PDF forms only a very small number of people even referenced using PDF forms. Sure normal hardcopy form duplication was mentioned. But the use of interactive PDF forms was left to a minority.

    • Low Usage Document

      Just like the use of PDFs for detail pages, documents with a low usage also where seen as more cost effective delivered as PDFs.

    • Web pages not a formal document

      This was a very interesting comment.

      It seems that the very volatile nature of the web page doesn’t make it a highly considered  paper replacement.

      Where as PDF’s, which are just as volatile, maybe because they come from a process close to the formal document are seen as more formal, stable.

      Interesting perception.

    • DRM / Security

      Contray to what publishers and the legal department may tell you;  the use of PDFs to enforce DRM or any type of security is very low on the reasons to use PDFs.   In fact I would presume the usage of security features of  PDF documents is generally low . Which in a way is a good thing – accessibility wise.

This rounds off the reasons to use PDFs over web pages for content delivery.  Still I hope that this continued PDF madness does ease up a little.

However I fear we will not be seeing this real soon, until web publication and print styles become as easy and effective as PDFs.

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