My New Favorite Tool for Reviewing PDFs: Okular | Hacker News Reader

My New Favorite Tool for Reviewing PDFs: Okular

harriskenny.com

172 pointsjrepinc68 comments

I just evaluated Evince, Okular, Foxit, and Acrobat for annotating PDFs.

My particular use case is to annotate emails, spreadsheet, etc., and merge them as exhibits into a legal brief.

After annotation, the other programs can export the original or it export the annotation layers but it could not give you a PDF with both the original and the annotations merged into one layer. This was a deal breaker.

With Okular you can print the PDF with the annotations as a new PDF to make sure your annotations are always visible. With the other programs the annotations are on separate layers which can get hidden on purpose or by mistake.

I found no other free program that could flatten the layers.

Okular deserves to be better known.

Have you found any software for exporting annotations (especially highlighted text)? Ideally, I would want to highlight text, select graphics, and have the software let me export those to PDF or doc/odf. My use case is reviewing academic papers.

I looked into Xodo and Foxit, but they don't offer what I need.

Have you tried Zotero with the Zotfile extension?

In theory, shouldn't every PDF viewer support printing... and both macOS and Windows 10 support printing to PDF... which flattens the layers?

Just tried it with macOS Preview and totally flattens it, the annotations pane lists nothing, I can't select/move annotations... they're permanent.

However, also just tried with Acrobat Reader on macOS, and infuriatingly after selecting the system's "Print to PDF" Acrobat pops up an error saying it doesn't support print to PDF. WTF. Why would they intentionally go out of their way to disable that?

Because they sell PDF creation tools: https://acrobat.adobe.com/us/en/acrobat.html?promoid=C12Y324...

> Why would they intentionally go out of their way to disable that?

I hope that https://en.wikipedia.org/wiki/Intel_80486SX is a not-excessively-snarky reply by appeal to history.

Try CUPS-PDF. I don't know if it still works but I've used it in the past to save PDFs from programs that stubbornly refused to allow it.

https://www.cups-pdf.de/

I just tried in Evince and you can print an annotated document to flatten it just fine.

Can you show me how?

I'm using Document Viewer aka Evince 3.28.2 on CentOS Linux release 7.6.1810 (Core) and I don't see an option to print the PDF with annotations.

It's just the normal print option. Fill out the form, Save As with the form filled out (not sure if this is necessary), print in the main menu

> Okular deserves to be better known.

s/Okular/most KDE software/

xournal does this.

I really enjoy Okular, it's fast, looks good and has smooth-scrolling (looking at you Foxit). However, I have been forced to use Foxit when dealing with annotations, because a lot of times Okular simply cannot display them if they were created in other programs.

I discovered Okular late in my dissertation-writing. I was pretty thrilled to discover that it could display annotations made with Acrobat. This was my advisor's preferred way of interacting, since I was somehow not able to interest him in learning git or LaTeX. At the time it was far better than evince. I've also found that it does a better job with big complicated pdfs produced by graphviz.

Okular is actually the reason I created Polar:

https://getpolarized.io/

Well, one of the reasons.

First, if you like Okular, you're stuck if you want to run on any other platform. It doesn't work on mobile, it doesn't work on the web, doesn't work on Linux, MacOS or Windows [1]

Additionally, there were pretty severe bugs when I used it and there were 1-2 long outstanding bugs regarding annotations that weren't fixed for nearly a decade.

The main issue with PDF annotations also applies. If you use PDF annotations it means mutating the PDF which has all sorts of problems.

I've had issues where you're working on Okular or Preview or Acrobat and then try to use another app and your annotations simply don't work or the PDF is corrupted in some weird way.

Having an immutable PDF solves that problem which is the avenue I went with in Polar.

Polar supports Web + Linux + Windows + MacOS. It also supports annotation without mutating the PDF and it's VERY hackable since it's just based on Typescript - which is one of the features I wanted.

We're very close from having mobile too and just need to clean up some CSS.

Anyway.. would LOVE your feedback if you play with Polar and find it doesn't perfectly nail your use case.

I'm actively developing it now and I'm pushing 1-2 releases per week.

1. My understanding is that while it DOES work on these platforms - it doesn't work WELL on them. Last time I checked there was no download for Windows or MacOS and you had to install the full KDE for these platforms.

I thought Okular was the default pdf viewer for Gnu/Linux systems with the K desktop environment?

Yeah I am super confused about that. I have been using okular for years and works on every common distro that I know of if you have KDE desktop or don't mind pulling in KDE deps.

Okular has a WIP mobile version for Android and Plasma mobile (with less features). The android build is broken because there isn't any icon, but running okularkirigami from the command line look great.

Also from reading the polar website, it looks like polar is more a document manager than just a document viewer.

> polar is more a document manager than just a document viewer.

It's both.. you just add the doc and double click it and you view it in polar in our PDF viewer.

"our PDF viewer" ? phone-home solutions fail

it's based on pdf.js ... which is developed on Mozilla. Both projects are open source. It's also free ;)

So why doesn't it work well on Linux?

I'm on GNOME, go to Gnome Software, search for Okular, click Install - boom it's installed. Since it's made available via flathub.org, Okular and the shared KDE platform libraries are installed as self-contained flatpaks. To ignorant me, looks and runs like any other application.

Nice app. Suggestions for Polar:

- Make it so that you can /draw/ on PDFs (Okular supports this). - Create an Android app which also allows local/offline usage.

Android app is coming... drawing isn't on the short term TODO though.

You found that you had to download too much bloat to use Okular so you made an Electron app? Im pretty sure you dont have to download all of KDE to use one of its apps, just the package manager and the libraries Okular uses.

I can't confirm if this is still the case, but a couple years ago you had a web installer for KDE on Windows and I could just deselect everything except Okular and a couple other stuff I wanted and that came out to a couple hundred MB disk space overall.

That was the windows installer for KDE 4, yes. I used to install it on every windows PC I had to use.

From a quick check now it is possible to install individual applications (Okular is not there):

https://community.kde.org/Windows

But it's not the same thing. At the times one was able to install the while kde4. That's a cross platform app!

I found this, which seems to be a build of Okular for Windows: https://chocolatey.org/packages/okular

(I haven't tested it -- happy Okular Linux user here. It was linked from the site you linked, though.)

"apt install okular" requires an extra 195 packages and 194MB of space on a Ubuntu machine I have handy.

It's not all of KDE, but...

Somehow I don't find 194 MB that bad if the proposed alternative suggests a 197 MB download as "probably easiest to install", but why let details like that let an opportunity to promote your project over someone elses go to waste... If someone with a Debian box handy wants to try how much in dependencies the .deb pulls in...?

The snap package linked in GP is also ~200MB. If you're the kind of person to be frugal with your hard drive, that's cool. But I don't think an electron app is the answer.

The Electron bloat of Polar buys you much better cross-platform features than the KDE bloat of Okular.

Okular is ok as long as you run only linux. In theory you could run it also on macOS or Windows, but you have to jump through the hoops. That's not optimal for a productivity application.

What kind of cross-platform features does Electron provide that Okular does not have?

I just told you: a friggin installer. All cross-platorm features are inconsequential if you can't easily distribute the application on multiple platforms in the first place.

Here in linux land we don't give a damn about installers. We prefer to install and update all software via a single interface.

What can you possibly object to about how it runs on linux? Its wholly reasonable that kde apps all build on the same foundation rather than each one bundle their own version of libraries.

If the entire rest of your desktop happens to be based on gnome for example you end up with *doctor evil expression" HUNDREDS OF MB of extra libraries once the first time you install a kde app. Perish the thought.

Did I say something in my comment that makes it sound like Okular doesn't run amazingly well on Linux?

I was talking about if you run it on Windows or MacOS.

> First, if you like Okular, you're stuck if you want to run on any other platform. It doesn't work on mobile, it doesn't work on the web, doesn't work on Linux, MacOS or Windows

You did directly say it doesn't run on Linux. Even with your qualification I don't think that's fair. It requires the KDE libs, yes, but that's not really a high cost apart from some disk space. Apart from that, it obviously runs perfectly well even in another desktop environment. I even use it on my Chromebook.

AH!!! ok.. definitely my fault. I meant to say it's not really cross-platform and doesn't run on all platforms.

This was a big requirement for me - the ability to move between all platforms.

I can't edit my comment but I screwed up and made it sound like Okular doesn't run well on Linux.

It does! It runs great on Linux. I meant to say it's not really cross-platform.

I just re-evaluated and I can't figure out how to download Okular for Windows/MacOS.

They have a Windows + MacOS page but they don't seem to actually have downloads.

Because Okular is build with Qt5 and the KDE Framework 5, Okular is with _little_ work cross-platform. There are nightly build available for Windows: https://binary-factory.kde.org/job/Okular_Nightly_win32/ I didn't try it, but I hear the Dolphin build (https://binary-factory.kde.org/job/Dolphin_Release_win64/) work well on Windows (just the terminal part is not available).

Wow! Thanks for the self-promotion :-) Polar looks perfect for an academic environment. From a quick look the only thing missing is some kind of bibliography/doi integration.

We're working on it! We parse the DOI now and we're going to implement unpaywal DOI lookup for extended metadata. It's probably going to be a few more weeks before this is fully integrated though.

> You have so many rounds of back and forth on collateral that it’s clear you don’t have strategic alignment and it’s spilling over into stifling execution.

What does this sentence even mean? Could someone ELI5 it to me?

you're changing the content so much that its clear the group doesn't have agreement on what should be created, so much that it's now spilling over to getting stuff out the door

I had the same reaction. I started pulling my hair out at: "There are also tons inefficient ways"...

For PDF annotating/collaboration, Xodo for the web deserves to be better known: https://www.xodo.com/app/#/

It displays/creates standard PDF annotations. You can collaborate with people online if you want, or annotate files on your computer without uploading them to a server (it uses emscripten/wasm/pnacl client side).

For those wanting to try okular on macos, it seems easier to setup via homebrew ( https://brew.sh ). The steps are:

$ brew tap kde-mac/kde

$ brew install cpanminus (needed for KDE-mac/kde/kf5-kdoctools)

$ cpanm URI

$ brew install okular

Then go make coffee while things compile.

source: https://github.com/KDE-mac/homebrew-kde

Okular is the only PDF reader that could handle PDF on my previous slow computer. Windows was a breeze but I always had problems with PDF on linux before I could settle for okular.

It bugs me that it's easier to select text with the underlining tool than with the select tool.

PDFs are kinda weird because there are somehow always PDFs that slow one viewer down but usually another viewer is fine. E.g. I have PDFs where Okular takes a couple seconds to render the first page, while LLPP renders it much faster. And vice versa -- which is the confusing part.

I work in publishing and we use PDFs extensively for proofing manuscripts. If you ever need to compare across PDFs, I created a small tool for it:

https://www.parepdf.com/

I really like diffpdf: http://www.qtrac.eu/diffpdf.html

How does okular compare to zathura (which can use mupdf or poppler as its pdf backend)?

Okular is to Zathura as Acrobat Reader is to Vim. :-)

My favorite tool for extracting data from PDFs: Tabula https://github.com/tabulapdf/tabula

One tool that doesn't seem to get the attention it deserves is Marginnote. I spent a bit more money than I should have on it, but in terms of reading, annotating, and making notes from PDF's I don't think there's anything else even close. I particularly love the ability to create a mindmap, flashcards for spaced repetition, and native export to evernote. https://www.marginnote.com/

When I'm on windows I'm always puzzled about how Adobe Reader is slow and has tons of features I will never going to use. Just let me get to duplex printing dialog, adobe!!!

I mostly use Okular for navigation and printing, but it also has a great feature of letting you select area of the document and either copy selected text or image into a buffer. This doesn't sound like a lot, but it makes working with pdf documents really comfortable.

I use okular on gnome when I absolutely need to annotate the PDF, I could not find other alternatives. okular is heavy and slow but it gets the job done when it's needed. I hope calibre can support annotations one day for the file formats it supports.

99% of the time I use evince to read PDFs though.

Okular is also wonderful for epubs if you documents ever move to that format.

Okular is great for epubs in that it can show them as a single document whereas most programs break them in to chapters that can't be searched across. However, it can also be terribly slow on some epub files even on a fast PC [0]. It also has problems rendering some files that other readers like epubreader have no problem with.

[0] https://bugs.kde.org/show_bug.cgi?id=359932

If only there was tool which would render my annotations in TeX, it'd make reading papers so simpler. Meanwhile, Okular

Yes yes yes and I am very thankful to the KDE on Windows builds programs.

Okular is awesome for reading .djvu file as well. Love it.

On Emacs use pdftools. Qed.

I love emacs but pdftools is kind of meh. You need it for pdf tools and a different addon to read epubs that works differently.

Then it uses a lot of memory, scrolls a little slow, and doesn't remember your place in a document.

Zathura remembers your place and reads epubs and pdfs while using less ram. Conversion between epubs and pdf seems to preserve the text but often results in ugly docs that are less pleasant to read so a good solution needs to support both.

I would love someone to improve document reading to the point where I COULD use emacs for document reading.

I used to use Okular before.

Even now when ever I try to use it, it is slow, and e eating up a lot of ram, scrolling doesn't look smooth enough. Whenever loading a new page, load time is clearly visible it used to work fine back in 2017.

My main desktop environment is KDE Plasma but I use evince for now while reading.

This is a terribly written article. Needs some serious editing.

"You have so many rounds of back and forth on collateral that it’s clear you don’t have strategic alignment and it’s spilling over into stifling execution. Hate to say it, but the tools aren’t the problem here."

What does this even mean???

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