Ask HN: Should PDF Be Replaced?
12 comments
PDFs are great. Epub sucks, mobi sucks. Let us continue to prioritize file formats that aren't garbage.
They do different jobs. Epub and mobi are just fine when you're reading a layout-free document.
PDF is good if you use SumatraPDF :)
I've long railed against use of PDFs for documentation largely on the basis that they're so painful to read online.
My views started shifting when I had access to a 9" tablet, and later an iMac Retina with a 5k screen.
What's completely sold me however is the 13.3" e-ink tablet I picked up earlier this year.
It has 1650x2200 resolution 16 shade greyscale at 207 dpi. Roughly the size of a sheet of US letter or A-4 paper. And it is delicious.
The problem with PDFs is not inherently PDFs. It's that computer screens and mobile devices simply stink for reading typeset content. Especially laptop displays.
PDFs can go wrong, and trust me, I've seen some bad ones, but they're bad for the same reason there are unreadable websites and shitty apps: designers with no knowledge of how to or interest in serving the needs of readers, and rather too much firepower at their disposal, aimed at foot.
The iMac display, when I happen to be in front of it, is wonderful (and I like others wonder why the 5k display format never took off --- it really is a sweet spot between 4K and larger devices, to say nothing of the flood of low-quality low-resolution monitors still crowding stores, online or B&M). With that display, I can view two-pages up, and have space left over for other work (a frequent requirement), as well as single-page views.
I'm not much enamoured of Adobe or what it's done with PDFs. Editability, PDF forms, and DRM are all poorly-behaved or malignant. (PDFs aren't intended as a modification format, forms ... should be addressed by other mechanisms, and DRM is cancer.) But the stock format itself does a job, does it well, and supports extensions including underlining and notetaking. These could be improved, but the fundmaentals are good.
The main problem with PDFs isn't PDF's. It's shitty device displays.
A low-quality printer manages about 300 dpi, and high-quality ranges from 600--1200 (photographic). At 200--300 dpi, e-ink is well in the "as good as consumer printers" basis for resolution. Readability improves as ambient light increases, and the experience under direct sunlight is excellent. Indoor-viewability varies --- the baseline white remains somewhat dark, and diffuse overhead lighting (flourescents) can result in glare, but that experience is no worse than with most emissive displays. Frontlights are available and work well. Colour remains a rarity, though it's not much of a price premium. Even where present it is muted, not vibrant. I can live with that.
But the really critical factor is size. I'd argue that the 8--10" range is probably the sweet spot, where reading most general works becomes viable. I read scans of older publications, including many journal and popular magazines, often scanned from copy with small fonts and quality issues, all but the worst of these are readable without requiring zoom on my 13.3" display.
Note that virtually all I have to say here applies equally to DJVU, another layout-oriented document format.
The issues I have with ePub and HTML are that they don't preserve formatting, don't offer hard pagination, often require scrolling (a horrible experience on e-ink, or frankly, on documents generally), and don't allow persistent reference by page.
My views started shifting when I had access to a 9" tablet, and later an iMac Retina with a 5k screen.
What's completely sold me however is the 13.3" e-ink tablet I picked up earlier this year.
It has 1650x2200 resolution 16 shade greyscale at 207 dpi. Roughly the size of a sheet of US letter or A-4 paper. And it is delicious.
The problem with PDFs is not inherently PDFs. It's that computer screens and mobile devices simply stink for reading typeset content. Especially laptop displays.
PDFs can go wrong, and trust me, I've seen some bad ones, but they're bad for the same reason there are unreadable websites and shitty apps: designers with no knowledge of how to or interest in serving the needs of readers, and rather too much firepower at their disposal, aimed at foot.
The iMac display, when I happen to be in front of it, is wonderful (and I like others wonder why the 5k display format never took off --- it really is a sweet spot between 4K and larger devices, to say nothing of the flood of low-quality low-resolution monitors still crowding stores, online or B&M). With that display, I can view two-pages up, and have space left over for other work (a frequent requirement), as well as single-page views.
I'm not much enamoured of Adobe or what it's done with PDFs. Editability, PDF forms, and DRM are all poorly-behaved or malignant. (PDFs aren't intended as a modification format, forms ... should be addressed by other mechanisms, and DRM is cancer.) But the stock format itself does a job, does it well, and supports extensions including underlining and notetaking. These could be improved, but the fundmaentals are good.
The main problem with PDFs isn't PDF's. It's shitty device displays.
A low-quality printer manages about 300 dpi, and high-quality ranges from 600--1200 (photographic). At 200--300 dpi, e-ink is well in the "as good as consumer printers" basis for resolution. Readability improves as ambient light increases, and the experience under direct sunlight is excellent. Indoor-viewability varies --- the baseline white remains somewhat dark, and diffuse overhead lighting (flourescents) can result in glare, but that experience is no worse than with most emissive displays. Frontlights are available and work well. Colour remains a rarity, though it's not much of a price premium. Even where present it is muted, not vibrant. I can live with that.
But the really critical factor is size. I'd argue that the 8--10" range is probably the sweet spot, where reading most general works becomes viable. I read scans of older publications, including many journal and popular magazines, often scanned from copy with small fonts and quality issues, all but the worst of these are readable without requiring zoom on my 13.3" display.
Note that virtually all I have to say here applies equally to DJVU, another layout-oriented document format.
The issues I have with ePub and HTML are that they don't preserve formatting, don't offer hard pagination, often require scrolling (a horrible experience on e-ink, or frankly, on documents generally), and don't allow persistent reference by page.
[deleted]
No, it has not lost relevance, and it will never be replaced by HTML. The PDF does one thing well: provide a fixed-format document that will (if the specification is followed) render a document with near-pixel perfect precision for decades into the future. HTML cannot do that. The format has shifted already, and will shift again. Documents will break.
The format is not meant to be edited anyway. It's meant to be generated, perhaps marked up or filled in, but rarely edited. Almost everybody generates PDF from another source format. Complaining that PDF cannot be edited is like complaining that the output of a C compiler cannot be edited. It can, but you have to make the change in the source format, then regenerate.
Adobe's dominance of the graphics stage is annoying to me, but the PDF format is the one good thing they have brought. The format is open, documented, cross-platform, standardised, and even has an archival subset (PDF/A) that can protect data for as long as we need to. It can be generated from any source, any program, and any scan, and unlike real paper, will never degrade with proper handling. In other words, vive la PDF.
The format is not meant to be edited anyway. It's meant to be generated, perhaps marked up or filled in, but rarely edited. Almost everybody generates PDF from another source format. Complaining that PDF cannot be edited is like complaining that the output of a C compiler cannot be edited. It can, but you have to make the change in the source format, then regenerate.
Adobe's dominance of the graphics stage is annoying to me, but the PDF format is the one good thing they have brought. The format is open, documented, cross-platform, standardised, and even has an archival subset (PDF/A) that can protect data for as long as we need to. It can be generated from any source, any program, and any scan, and unlike real paper, will never degrade with proper handling. In other words, vive la PDF.
PDF should be replaced since it is absurdly complex, yet HTML cannot do it. The important requirement is for multiplatform print-oriented rendering, HTML is far too free-flowing and differs too much between viewers. Any replacement must have this basic property.
ePub is probably the best alternative intermediate format.
I have a strong preference for PDF or DJVU, but for devices which can't display documents at full scale (most below about 8" diagonal), ePub at least provides access to the content.
I have a strong preference for PDF or DJVU, but for devices which can't display documents at full scale (most below about 8" diagonal), ePub at least provides access to the content.
ePub are packaged HTML/CSS/SVG, and entirely dependent on their changing specs. That's no good for many of PDF's uses. Printers these days can print PDF directly. With ePub they'll eventually need to include an auto-updated version of Chrome? If we want to replace PDF entirely, we need a stable print-oriented format.
Hrm...
So I know that ePub is a packaged bundle of HTML + CSS. I could see SVG in there. Does it also include JS?
A static or slow-moving subset of HTML could be reasonable. Again, what ePub manages to achieve by way of single-file distribution and reflowable (but pageable) text is ... useful for mediocre devices.
But if it does keep us on the Google-mandated spec-escallation treadmill ... Yeah, that's kind of awful.
So I know that ePub is a packaged bundle of HTML + CSS. I could see SVG in there. Does it also include JS?
A static or slow-moving subset of HTML could be reasonable. Again, what ePub manages to achieve by way of single-file distribution and reflowable (but pageable) text is ... useful for mediocre devices.
But if it does keep us on the Google-mandated spec-escallation treadmill ... Yeah, that's kind of awful.
>So I know that ePub is a packaged bundle of HTML + CSS. I could see SVG in there. Does it also include JS?
ePub does include Javascript, including the SVG ability to include a script element, which IMHO shouldn't have ever existed in the first place. But the JS version is never specified, and it's unclear what's really supported besides the navigator element which is mentioned in the spec.
In fairness, PDFs also support JS, but most PDF viewers are sane enough to just ignore it - haven't done a check of ePub readers, but I suspect it's not much different.
>A static or slow-moving subset of HTML could be reasonable.
Latest ePub specs (v3.1+) explicitly commit to supporting latest HTML5. Quoting the 3.2 spec:
"The biggest change in EPUB 3.2 is the relationship to the core web specs of HTML, CSS, and SVG. In the past EPUB has pointed to a particular dated version of HTML or CSS. EPUB 3.2 now officially supports the current versions of HTML, CSS, and SVG, as defined by the W3C. These versions will evolve over time, allowing EPUB to remain up-to-date with the web."
ePub does include Javascript, including the SVG ability to include a script element, which IMHO shouldn't have ever existed in the first place. But the JS version is never specified, and it's unclear what's really supported besides the navigator element which is mentioned in the spec.
In fairness, PDFs also support JS, but most PDF viewers are sane enough to just ignore it - haven't done a check of ePub readers, but I suspect it's not much different.
>A static or slow-moving subset of HTML could be reasonable.
Latest ePub specs (v3.1+) explicitly commit to supporting latest HTML5. Quoting the 3.2 spec:
"The biggest change in EPUB 3.2 is the relationship to the core web specs of HTML, CSS, and SVG. In the past EPUB has pointed to a particular dated version of HTML or CSS. EPUB 3.2 now officially supports the current versions of HTML, CSS, and SVG, as defined by the W3C. These versions will evolve over time, allowing EPUB to remain up-to-date with the web."
Thanks.
Much of HTML5 is IMO pretty good in that it is explicitly structural. Mark Pilgrim's Dive Into HTML5 is excellent at both describing and being an exemplar of good HTML5 design. (The markup is remarkably sparse and clear.)
Canvas, interactivity, DRM, not so much.
Much of HTML5 is IMO pretty good in that it is explicitly structural. Mark Pilgrim's Dive Into HTML5 is excellent at both describing and being an exemplar of good HTML5 design. (The markup is remarkably sparse and clear.)
Canvas, interactivity, DRM, not so much.
The specification is ever-growing and out of sight. Adobe's proprietorship of PDF almost comes off as lure for needing to purchase Acrobat for simple editing. They really do not want other vendors or software firms having the leverage they do for a product so basic it shouldn't really exist.
The industry dominance Adobe has on document formats is a burden to users that deserve something open.