HACKER Q&A
📣 pranshum

Why are PDFs still heavily used?


PDFs are terrible to view on mobile. They have accessibility issues, navigation is painful, the content is static, and so on [1].

Web standards fix many of the problems. So why are PDFs still used, particularly for publishing reports?

1: https://www.nngroup.com/articles/pdf-unfit-for-human-consump...


  👤 t-3 Accepted Answer ✓
> the content is static

Why are you saying this like it's a bad thing? Why would you want dynamic content in a document format?

You can't give someone an epub and tell them to read page 197. You can't look at a webpage and know how it will look when you print it out. You also can't just netcat an ebook to your printer and get useful output.

What alternatives do we really have? PDF is the most widely supported format outside of plain text (arguably more widely supported than text actually, with phones being the major computing device). I haven't seen an ebook format that can correctly and consistently deal with code sections, inline images, quotes, font styling, paging, etc (maybe more a software issue than format problem, but if nobody can make it work right, the format isn't blameless).


👤 bob1029
The consistency of the format. PDFs are pretty much the only realistic way to convey items like legal documents to a wide range of customers. I certainly wouldn't want to receive my legally-binding bank account documents as a pile of HTML soup that would render arbitrarily (or not correctly at all).

I also have a rule about reading PDFs. I almost universally print them off to actual paper if it's more than 2-3 pages worth of content. Printing websites is a non-starter.


👤 PaulHoule
Personally I love reading PDF files on my iPad (or cheap Android tablet for that matter.) I can load 100 books and even more technical papers and read them on the bus, spinning at the gym, in bed, curled up on the couch, as a passenger in my car, etc.

Posting papers from arXiv to HN I have a choice of pointing to the HTML abstract or the PDF and overall people express preference for the PDF and I believe I get more upvotes for the PDF.

I can see a phone being a little too small though. PDF does have features that make it possible to make a PDF which is reflowable like an HTML document for the sake of accessibility and better UX, but those features are complicated as hell and rarely used.


👤 k4ch0w
So, it seems a little strange now but when everything was a MS Word Document you had problems with the format. It would look amazing on your machine but if someone else opened it in a version higher or lower than yours or on a different machine things could look really funky and bad.

Thus, PDF was a game changer. Basically, no matter what machine you opened the file on it would look exactly the same. It kinda sucks you can't edit it or have to use special tools to parse it but when it comes to readability across devices it cant be beat.


👤 stonogo
Almost all of the complaints in the linked document boil down to "PDFs are not websites," which is ironic, considering that is the main benefit to PDFs.

A bunch of them are just dumb assumptions, like vague complaints about accessibility, ignoring the fact that PDFs have supported screen readers, alt text, etc for longer than the web has.

I laughed out loud at the assertion that PDFs are "stuffed with fluff" and the web is a model of focused, concise writing.

"Jarring user experience" and "Cause disorientation" are the same complaint rewritten to highlight different aspects of one problem.

Web sites and PDFs are different tools serving different needs. The complaint that PDF content is "static" is, confoundingly, both untrue and entirely the point. PDFs have support Javascript, media embeds, advanced navigation tools (hyperlinks, cross-refs), and more, for years and years... but most people don't encounter much beyond formfills and hyperlinks, because the rest of that stuff is not what people want out of a document format.

In other words, all the consultants can write all the words about how PDF should be the web, but the market has spoken, and PDFs are the way they are because they meet real needs. Figuring out what those are might be a better use of time than shouting into the wind.

Now that I think about it, why should I have to throw away thirty years of PDF-compatible software because nobody bothered to make a decent PDF reader for your phone?


👤 morsecodist
I have a love hate relationship with PDFs, the hate mostly comes from parsing them. However, I think they are often the best thing for the job. A PDF is totally portable, your images and fonts are included in the file (I know you can do that with HTML but it is not how it is typically done), everyone can open them on every device, and you know when they do they will see exactly what you do, even if it may have a bit of an awkward aspect ratio. You also know it will look good printed out which is a huge pain to achieve using web standards. Most programs used by normal people (word/google docs, powerpoint/slides) have an intuitive export to PDF flow while a web page export, is usually more complicated and dissimilar to the document they originally created. There are whole categories of questions you need to answer about your formatting using web standards that are just not even a consideration in PDFs and most people don't want to need to think about that just to share a document.

👤 jasong
In my experience PDFs are mostly used to ensure what you're seeing is what everyone else is seeing. If I sent out a Word or Powerpoint doc, I could be 90% sure someone would have a formatting issue. Maybe their default margins are different or they don't have the same fonts installed. It's a better format for the reader when they don't require edit access.

Google Docs + MS Office has probably figured this out by now, but there's also ton of historical momentum keeping it in use.

As a financial auditor I remember being baffled how people would go out of their way to create paper processes. A spreadsheet that requires confirmation would be printed, signed, stapled to another piece of paper - all so I can remove the staples and scan it to track digitally in our audit software. At least I knew sending them a PDF would come back looking the same...


👤 stocknoob
If you can’t list their numerous advantages, I don’t think you should be asking for their removal.

https://en.m.wiktionary.org/wiki/Chesterton%27s_fence


👤 rchaud
PDFs are the only choice for portable read-only information. You click a button in Word and it exports with 100% fidelity exactly what you had on screen. Open it on a phone, or tablet, it retains its original size.

Web standards may have caught up, but nobody is sending anybody .mhtml files. I'm pretty sure most email providers would flag emails with such attachments as malicious.


👤 pwg
Because most businesses/governments are solidly stuck in the "sheet of paper" paradigm, and PDF provides a way to "make electronic" all those sheets of paper.

And once the old paper based process has been "made electronic" by using PDF's, they don't bother with trying to continue past a "sheet of paper" metaphor.


👤 runjake
- The content is normally static.

- They render consistently on any mainstream platform, without access to external resources.

- They load, scroll, and zoom relatively quickly on mainstream platforms.

I don't think PDFs are terrible to view on mobile. I think it works out pretty well. I prefer viewing them than the mess that is an HTML page with CSS. Usually whoever authored it ddin't do a good job of making it pinch/zoomable and accessible.


👤 dctoedt
In the contract-negotiation world, signature versions of contracts are pretty much always Word documents that are saved to PDF and then "signed" electronically — a PDF document has more of a "feel" of immutability, even though altering a PDF is trivial for anyone with Acrobat Pro or equivalent, of course.

👤 minimaxir
PDF content is consistent across devices.

The lack of changing on mobile is technically a feature.


👤 sergiotapia
It's the only format that I can know with relative certainty that will keep show the same visuals across many devices and platforms. That's very important.

Word/excel/powerpoint all do whatever they want.


👤 thow_away_34564
I think the answer is in that PDFs are used to convey 90%+ static content offline in a way where you could open up 10-year-old PDF and it will still look exactly like it did the day it was created. Because of this is it the system of record for reports in business, government, academia, and other organizations.

The other use case are fillable forms that are legally binding. In larger business or the government where you have your identity tied to a private key, you can sign a PDF with it.


👤 goethes_kind
PDFs are easier to view on mobile than most websites containing the same range of content. Basically any graphic on a website is poorly displayed on mobile.

👤 joejoesvk
this is such a HN question...

👤 eimrine
MS Word's formats are worse.

👤 1attice
Because of the power of metaphor.

A PDF is, in the popular consciousness, a digital form of paper. Anything that could be on paper? PDF.

Think of it as an FFI for the paper-based OS that our civ still runs upon (and may always.)

Like, network-based civ is kind of like a VM, and numerated paper documents (laws, etc.) are libc, and when you want to call out to the underlying reality, you use PDF.


👤 ehutch79
It's a print format. They're meant to replicate the printed output.

Sometimes I wonder how in touch Nielsen is with the real world.


👤 Gordonjcp
What would you replace them with?

You can't use HTML, because it's totally inconsistent. You can't use Word docs, because they're totally inconsistent and not cross-platform.

What format can you think of that you can use to describe how each page looks, right down to fractions of a millimetre?


👤 CamperBob2
Because they will still be readable a hundred years or more from now. Your favorite format, whatever it is, probably won't be.

👤 nottorp
Get a 10" tablet or a laptop. It's painful to read any format on a phone.

👤 ihatepython
Web standards don't fix any of the problems.

I hate reading web pages on my phone. PDFs are far superior, especially on tablet.