PDF annotations private beta 2


This topic is closed. The new beta can be discussed here: PDF annotations private beta 1

Getting Started

Our new app is called MetaPDF and is implemented as generic, standalone application to annotate PDFs in Google Drive:


The goal of the private beta is to get early feedback on our new PDF annotator. Things are missing and things might break. Please keep this in mind.

Feedback and reporting bugs

Please post all feedback and bugs in this thread. We’ve tested with hundreds of PDFs of various sources but PDFs can be complex and there are many programs out there that write corrupted or non-standard PDFs. If you run into issues with a particular PDF (e.g. can’t open or can’t write/sync) and it is not too sensitive or private share it with andreas@paperpile.com.

Feature highlights

  • Annotations are saved natively in the PDF and can be read and edited by any standards compliant PDF program.
  • Annotations are synced back transparently to Google Drive.
  • Annotations are written locally, i.e. the PDF is never transferred or stored on our servers.
  • Properly displayed highlight annotations that are not overlays over the text but “painted” natively on the page.
  • Streamlined UI with keyboard shortcuts (e.g. select text and try pressing 1,2,3,4)
  • More to come.


  • Step 1: Initial release as standalone app without sharing and collaboration.
  • Step 2: Sharing and collaboration.
  • Step 3: Allow opening PDFs from Paperpile in MetaPDF
  • Step 4: Integrate MetaPDF as Paperpile branded viewer in Paperpile.
  • Step 5: Show highlights and notes of PDFs in Paperpile.

Known issues

  • Currently, MetaPDF is Chrome only, will work on other browsers in the future though.
  • Sometimes Google Drives can’t read PDFs and shows an error “403 Forbidden”. Reloading MetaPDF should help.
  • Only works with files you own at the moment. If you open shared PDF and you want to save it might work or you get a “forbidden error”.
  • Colors and design are not final and have rough edges.
  • Features that are planned but not implemented will show a “Coming soon” message.
  • In the unlikely case that MetaPDF corrupts your PDF file you can revert to an earlier version within the last 30 days using the “Manage versions” feature of the Google Drive webapp.

Support for PDF annotations

Wow, the app looks very promising already. What is your current timeline for roadmap steps 1-5?


Thank you for including me in the beta. So far, I have to say, that you did an excellent job! For me, it does what I need while being simple and elegant. The first thing I did was verify that it creates standards compliant PDF annotations. I verified this by opening a PDF file from my desktop-synced Google Drive folder. I opened the PDF in Adobe Acrobat 11.0.10. I then synced the PDF file to my Samsung Galaxy Note 4 and opened it with Foxit MobilePDF - PDF Reacer

The annotation was perfect! You have outdone yourself. That fact that you nailed this puts this product above all other cloud-based PDF annotation tools.

Also the fact that you have syncing working with Google Drive is another huge boon for this product.

This was just a quick test, but I’ll begin to use it as my primary PDF annotator. Hopefully this will give me more opportunities to leave feedback.

Thanks much!


Thanks, good to hear that the first reactions are positive.

Timeline is hard to tell. Depends on how many issues we find in step 1. We have a clear plan for step 2 but it adds another layer of complexity that is also hard to predict how difficult it will be.

3 and 4 should be relatively fast, we maybe even skip 3.

Step 5 is farther off. The reason being that while the annotator is pretty much independent of the rest, integrating the notes in a meaningful way needs some serious thought. We’ve got many ideas from our users here that we need to find the right set of features without adding complexity to the Paperpile UI.

I hope I can give more specific estimates when we are through step 1 and 2.

Thanks for being the first trying MetaPDF!


Thanks so much for the positive feedback. If you run into any issues let us know.


Hi Stefan,

MetaPDF is just awesome. One of the best annotators for linux ppl. I would love to have a auto save feature. Its a matured app, but few more things:

  1. Is it possible to set the title of the browser tab to the name of the file. As you do that in Paperpile/Google Docs.

  2. And is it possible to show first few lines of annotation than showing the whole thing (Only for large annotations). When I have too many annotations I need to scroll the page and also scroll the annotations. Having a sync between the two will be the best.


Looks like I’ve run into a little buggy behavior. It seems that the text in the annotation list on the left is not matching up with what is highlight in-text. Please see the picture. FYI, these highlights were made in Acrobat originally.



Found another one. Hitting refresh in Chrome closes the currently open PDF.


Found another issue. This involves the same PDF in my previous post. Please see the attached screenshot to get a better idea of what I’m talking about. I have a PDF that I had been highlighting in a bunch. I created a copy of it. I opened the copy in MetaPDF. I then opened that same PDF in and the original in Acrobat and I had the results you see in the pic. The highlighting is funky in the MetaPDF version and the comments are also missing.



I tested this with another, smaller PDF and the same issue came up. It appears that MetaPDF is not happy bringing in previously existing annotations. Annotations made in MetaPDF work great in other apps, though.


Syncing But Not Syncing

When opening a PDF for the first time, I get the “are you sure you want to navigate away from this page” warning when I try to force a sync. When I click “Cancel” on this pop-up. The “syncing…” status under the “Save” menu does not change until I try to force a sync again.



I first tested the two features most important to me: exporting annotations and opening annotated PDFs from other apps. I saw that the first is not yet implemented, but that there is a menu item for it. I hope to see this soon. I was also able to open a PDF I’d annotated in GoodReader on iOS and have all the highlights listed without doing anything, which is great and bodes well for mobile integration with Paperpile even if the PP iOS app is a ways off in the future.

Personally I would like the annotation sidebar to be expandable. I have a large cinema display monitor and there is room to have more than such a narrow column. Or perhaps an annotation only view which is full width?

I like that one can search annotations, but something is needed to be able to more easily navigate and search comments as well. I suggest <> buttons that let you jump to the previous/next comment and a search bar at the top of the comments bar as well.

Finally, and this may be in your longterm roadmap, but it would be really neat if one could click on citations in a PDF and automatically add them to Paperpile with a note as to which paper they were found in…


We’ll se what we can do with the sidebar.

In principle comments are searchable through the annotation search bar on the left and if you click the results you should get right to the comment. Searching the comment bar is conceptually tricky because they comments are not a list but have a fixed location and would feel a bit redundant.

As for exporting annotations: What would you do with it? Import in other programs? What format would you like? What would be your perfect solution here?


Can you reproduce? If so can you send us the PDF and the exact steps. Thanks.


My current workflow involves annotating PDFs in GoodReader on the iPad and then exporting the annotations to two locations: (1) Evernote where I keep them so that they will be discoverable via Evernote search. (2) Workflowy. I use workflowy only when using the annotations for a paper or a lecture. In this situation I use the outlining program to help me give some structure to the annotations so I can see the flow of the argument and to trim away those annotations which are not useful for the project at hand. I know other people who do something similar using the Scrivener app or various other mindmapping/outlining apps. For me a plain text file is sufficient since Workflowy can convert plain text on copy-paste, but I know that some people like to have OPML export so I’m mentioning it here.

One thing that is an issue for such annotation export is how much metadata to include. Personally I just want the page number and I want it on the same line as the text (otherwise causing problems for Workflowy import, creating two items in the outline rather than just one). I have a script in Editorial on my iPad which removes a lot of the GoodReader metadata for me using various RegEx searches. I understand that if you are allowing collaborative annotation it might be useful to know the date and name of the person who is doing the annotation/comment - but personally I would like to just have the text. (Perhaps with a heading like [Comment:] for comments so I know they aren’t quotes from the text.)


If any of you guys run into trouble with annotations being not displayed or imported correctly in MetaPDF or external readers, it would help us a lot if you could mail the affected PDF file to andreas@paperpile.com.


Is it necessary for the app to request full access to Google Drive (“View and manage the files in your Google Drive”)?

Or would it be sufficient to limit access to “View and manage Google Drive files that you have opened or created with this app”?

Personally I normally don’t use any third party applications which request full access to Drive to minimize the risk of a data breach.


Actually it should have this more restricted permission. I did not realize it hasn’t until you mentioned it and I double checked the code. I don’t see a reason why we would need the extended permissions. I hope there is no showstopper somewhere, but in principle we’ll do everything to use the more restricted permissions. Thanks.


I have also found a bug. When selecting sentences to highlight, the sentences are not properly highlighted but only a selection. The rest of the annotation leaves the text to the left.

Screenshot: http://i.imgur.com/TGmm59Y.png


@orschiro Nice catch. Could you send the PDF file to andreas@paperpile.com that I can debug our code to see what is wrong here?