PDF annotations private beta 1



Concerning zooming, why is it that in Chrome when I open a pdf in the browser (not using MetaPDF, but just the regular Chrome viewer) I can zoom and it stays “pretty”.

Regardless, the highlighting does seem to work better, and that’s more important.

Finally, it would be nice to be able to change the background color to make it darker (also like in the default Chrome browser). Don’t know why, but it’s easier for me to read when the whole screen isn’t so bright. (BTW, my monitor is broken such that I can’t actually lower the brightness of the entire screen. I’m stuck with the level its at). So, making part of the screen darker is my only option.


ADDENDUM 1: I noticed that the “change name” option when you click on the “auto sync” pull down menu doesn’t seem to work.


I’m not sure why you want to zoom in the first place. You can of course zoom the PDF and it stays perfectly crisp at all zoom levels. You just can’t zoom the whole tab via Chrome. I don’t see any use case for zooming the tab unless the menu font is too small. But I don’t think that’s the case.

The rename function is not yet implemented.


To be honest, I don’t generally zoom on purpose (at least in metaPDF). It may be that I sometimes accidentally zoom using the trackpad or mouse wheel and don’t realize it. But that’s sort of the point, I don’t even know that it’s zoomed a little bit, but I’ve found myself in that situation more than once, thus the suggestion to maybe have a popup say something like “Hey dummy, do you realize you’ve zoomed the tab? You’re going to mess up how the pdf looks!” I’m sure you can find a better way to say it though!



Today I have found a bug. I have made some notations and highlighting in a pdf with an Android App (Xodo) and uploaded the PDF to my Google Drive. When I open it with MetaPDF the first page of the PDF is blank, the rest is fine. Other PDF viewers show it correctly (Xodo on web, Xodo on Android, Goole Drive Reader, Okular, …).


Hi, thank you for the great app, it works perfect! Can’t wait to use it as default PDF app for paperpile!
Usability BUG When you click “add comment button” from highlighted text popup balloon the cursor focus stays at “Search annotations” so you won’t be able to type immediately =(

Feature request: I need the ‘sort by color’ feature for annotations, it is essential for color coding. =D

Another issue is default web browsing controls, besides arrow keys I usually use space-bar and shift+space-bar (which are the same as page-down and page-up but not everybody owns IBMish keyboard)


A note on links to bibliographies in PDFs – the “link” box drawn around the reference number is too small and obscures the number. This is problematic and leads to three issues:

  1. The box is too small, and I can’t tell what number is referenced in some cases. See picture
  2. If the reference is on a short page (such as the last page of the document), it doesn’t scroll to the reference, leaving me wondering which reference is being used.
  3. There’s no obvious way to get back to where you were in the document before you clicked the link. I sometimes just want to check out a reference and quickly go back to where I was.

Can you make the link box larger (or make it toggleable – I know where I can click in these documents)? Furthermore, it would be great if I could just get a small window (think picture-in-picture) that shows the area of the paper around the link destination as a preview. A back button to go back where you were pre-click would be fine too.


Another note: highlighting between pages does not work. The text is highlighted, but the highlight annotation is not applied.


It seems you have PDF made by LaTeX using a package creating internal links. That has nothing to do with MetaPDF.

Clearly we would love to have this feature being able to link citations within a document. But if it’s not encoded in the document already it’s not easy to add this information.

We hope we have some resources at some point to look into this either improving the experience for already existing internal links or adding our own links.

For now I’m afraid we just display exactly what’s in the PDF.


Good point. This edge case (in the very sense of the word) is currently not implemented.


re: focus bug: We’ll definitely fix that, I’m sure it has worked as expected at some point but got lost along the way…

Sorting by colors: I really like the idea. I’ve put it on our internal list of potential features and we’ll discuss this once Andreas is back from vacation.


Stefan, the major problem for me is that the green link box obscures the number. It doesn’t do this in Acrobat (see picture). I’m sorry if my request got mixed in with other thoughts/ideas.


This may have already been raised, but… when my sidebar is closed, MetaPDF thinks it’s still there and switches my cursor to a horizontal resizer. This makes it impossible to highlight up to the point where this happens. In the attached screenshot, my cursor was where the red arrow is; I had tried to highlight from “Pooling…”



Some things I noticed:

  • when typing in the annotation box on Ubuntu Chrome, the pdf starts to flicker with every keypress, as if it was being refreshed every time. Very annoying
  • this seems to be only happening with the left side-bar collapsed. As long as it is open, there is no problem.
  • opening an annotation box should also make it focused. Clicking again gets annoying
  • when typing in an annotation box, ctrl+enter should end the annotation and return focus to the text
  • highlighting of text gets rendered in the wrong location if the zoom level is set to page-width on some texts.
  • App tends to freeze when that happens
  • while highlighting text in pdf forms does work, commenting on it does not work (no tooltip menu)
  • the hovering annotation box in the legacy app is actually quite useful for general remarks or summaries that are not attached to a specific part of the paper. Would be great to see it come back with markdown support.

edit: just saw that the focus issue was already posted. Also +1 on the color sorting. Would be fantastic



Thanks so much for this annotation utility, in general I think it’s great! However, I do sometimes wrestle with highlighting, it seems very sensitive to flipping and highlighting a big chunk before the start instead of the one-liner after the start of my click. I also have occasional issues with the highlight margins not matching the paper margins (I can send you an example of this if that would be helpful).



First off - love this idea! I would like to use it most for collaboration – taking notes to share with others. It would be pretty ideal if the “document outline” exported to the “notes” section on paperpile. Is this a possibility?


I think there should be an undo button. I keep accidentally highlighting large bits of text and then taking time to find the X to remove it.

I am unsure how to create a document outline. How do you do that?


Actually there is an undo button in the menu. Also you can undo pretty much everything with Ctrl-z or on a mac Apple-z.

What exactly do you mean with document outline?


Off-Kilter Highlighting

Hello Developers,

I ran into a PDF exhibiting the displaced highlighting issue. Here is a screenshot:

Here is a link to the PDF: Community Involvement in School: Social Relationships in a Bedroom Community.

Thank you!


One suggestion: I annotated a pdf with adobe acrobat (on android), and that seems to have gone over well to metapdf, but the default adobe highlights are ugly bright yellow compared to the ones MetaPDF adds. Is it possible for metaPDF to just interpret those default highlights made in Adobe as the default highlights of metaPDF?

One bug: I deleted some highlights and sticky notes that I made in Adobe acrobat (on android) with metaPDF, and replaced them with highlights with comments, which is a nice option in metaPDF, but one I hadn’t spotted in Adobe. When I opened the pdf in acrobat (version shown below) on a macbook air. I get the error message “Dictionary keys must be direct name objects.” If I click OK, the same error window shows up again.

Adobe Acrobat DC on mac.
Architecture: x86_64
Build: 15.8.20082.147029
AGM: 4.30.58
CoolType: 5.14.5

I can email the pdf on request.

Second bug. The annotation report on the lefthand side of the paper nicely shows the highlighted text snippet, but has trouble with more exotic characters. The pdf itself shows the characters as intended in metaPDF

“The Chronicle ofS 0e 0eert knows merely that the plague ( wab 0a 0a’ ) spread throughout Persia,India, and Abyssinia (al-Habasha)”

“S 0e 0eert” should be “S ́eert”, and “wab 0a 0a’” should be “wab ̄a’” (but with the “-” above the “a”).



Could you, please, send the PDF file to andreas@paperpile.com. Thanks for your help in debugging!