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Comment by wongarsu | Hacker News Reader

To be fair, in my experience Chrome's and Firefox's PDF viewers don't cut it. They are good for a quick preview, but especially when printing they occasionally render things slightly wrong, which is unacceptable for a file format whose entire point is to look the same everywhere. Also forms.

That doesn't mean that there aren't any alternatives. Foxit for example is pretty good. But in-browser alternatives just aren't there yet

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pdf.js has had 26 pull requests merged in the last month. 5,622 additions and 6,991 deletions. That's just in the project directly, not in the dependencies.

Since it's such a quickly evolving project, I wondered where form support is up to. https://github.com/mozilla/pdf.js/issues/7613

Form support is not complete. Seems like it required quite a rewrite to get the foundation in a good place to finish it off.

Are there rendering bugs? Yes. See plenty here: https://github.com/mozilla/pdf.js/issues

Of course, Acrobat also has PDF rendering bugs, and other various bugs apart from the security issues mentioned (their JavaScript implementation for example).

As for printing... browsers aren't even good at printing HTML. The best browser for printing is based on the old Opera software(PrinceXML), and Safari is probably second. Remember the Apple display system used to be based on PDF rendering... and they do a lot with CUPS and graphic designers.

However, printing PDFs on many browsers can go directly to the printer or the OS (which mostly all support rendering PDFs directly now).

> Remember the Apple display system used to be based on PDF rendering

Does Quartz not still try to match PDF in the way its render structure is composed internally?

Is there a AFL type CI work flow for fuzzing pdf.js?

google it seems only return how to fuzz js engine kind of links.

Love to see write up of how to fuzz a JS application by doing AFL type mutations on the server return data, etc.

Chromium uses Pdfium, which is based on the Foxit code base, actually, since they bought some pieces of it: https://www.foxitsoftware.com/blog/the-interesting-history-a....

Actually I've never had rendering bugs with Chrome, though it's certainly happened with Firefox.

We don't find bugs with it it's just limited. Can't highlight, can't rotate individual pages, can't save rotated pages (you have to "print" it to "Save as pdf" again, awful ux)

Dumb question:

Why can't we just burn PNGs[0] or lossless JPEGs and just use OCR / other simple machine learning for text selection? Like, I get that there are some unfortunate souls out there that need to edit CAD documents in their PDF but for 99.999% of people PDFs do one thing that websites do not:

Print reliably well given a page format like A4.

I shouldn't have to wince ever time I open a PDF. They're so insecure that a no-click RCE only fetches $10k.

[0] Or ideally SVG, but there are some problems with fonts and licensing that I'm struggling to remember at the moment.

Accessibility, plus print is at ridiculous DPI compared to screen. To achieve compression you want to use the fact that there is a font being repeated across the page. OCR just isn't good enough.

Are you telling me that our compression algorithms can't compress a page of "e"s tighter than a page of random Chinese characters?

Accessibility is a fair point, but for print-to-file applications we're surely at the point where OCR can at least get the text to a readable format, no?

Because OCR is expensive (to write as software and to process for the end user) and very error prone, especially if your text is anything other than a 12 point black font in on a white background with no formatting (italics, underlines, etc.). If my document's information is valuable, I'm not going to be willing to rely on the quality of my recipient's OCR software to get a digitally readable copy of my work. I mean, at the very least, what if they're blind?

The general hatred for PDFs in the tech community is almost completely rooted in Adobe's initial decision to make PDF editing and creation cost $500. You have access to a document that want to make changes to, but you can't because it's a PDF and don't have access to the document source because the owner/publisher didn't provide that. It's a PDF because PDFs make documents that look the same everywhere, even when printed, which is and will remain critical to the purpose of publishing documents. Well, images don't solve this problem, either, because you still can't edit text in an image, and now you lose the ability to be sure about how they'll print (margins, scaling, etc.).

Furthermore, images, even compressed, are significantly larger than a well made PDF. For example, I've got a 6,700 page document of special ed student progress reports that include detailed, full-color charts and graphs of student progress with respect to goals. It's 60 MB. 8.5 KiB per page.

Then again, I imagine it won't be long before someone mentions LaTeX as a viable alternative, even though the one thing LaTeX isn't is portable. But LaTeX is primarily popular in the tech community because it lets programmers pretend to write code while they're actually writing documentation. Nowhere else will you find people telling you to use a set of programs that require a build environment when someone asks about the best home office application to use. (Yes, I know that LaTeX is a typesetting language. My cynicism is that some tech people tell others to use LaTeX when they're asked what word processor someone should use.)

Edit: Clarified second paragraph.

> Then again, I imagine it won't be long before someone mentions LaTeX as a viable alternative, even though the one thing LaTeX isn't is portable. But LaTeX is primarily popular in the tech community because it lets programmers pretend to write code

Rude remarks notwithstanding, LaTeX and its ilk let you make PDFs, which are indeed portable. Setting up LaTeX is the same as setting up any other program, some of which are not portable either. ShareLatex.com [0] also exists for the purpose of using LaTeX anywhere.

People recommend LaTeX because it's in another league when it comes to typesetting and rendering more niche notation. It's also not user hostile when it comes to binary files. LaTeX source files will always be readable decades later, <binary app here> makes no such guarantees.

Whether it's a viable alternative depends on whether the user wants to make a minimal learning investment or not. If they don't, google sheets > export to pdf always exists.

[0]: https://www.sharelatex.com/

dvi files are about as user hostile as it gets for a rendered document format, though

No the hatred for PDFs is that they're filled with bloat and horribly insecure.

As for OCR, we're able to handle underlines and italics for most fonts, though I take your point on colour. If it's especially bad they fail. Ideally it wouldn't be PNGs it would be some stripped down thing. Maybe even HTML with embeded CSS / images via data tags would fit the bill, but now we're bringing in XML-esque parsers and those are garbage too. I'm just so frustrated with dealing with PDFs. They serve a billion different purposes and they're good at none of them.

I've never noticed rendering errors, but my problem with the browser built-in PDF viewers is that they can't handle big complex PDFs, especially on older machines. They'll gobble up 4GB of RAM like it's nothing and start swapping on PDFs that Acroread or xpdf display in less than a second.

A counterpoint: for a while I was working at my uni's help desk, and we would ask all clients to print PDFs from Chrome as a matter of course just because it was so much more reliable at producing the correct output on paper, even when compared to Adobe Reader.

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