Transferring Annotations Between iPad & Macbook

Discussion in 'Mac Apps and Mac App Store' started by Tissue Paper, Jan 31, 2014.

  1. Tissue Paper macrumors regular

    Jun 18, 2012

    Currently I use Skim on my Macbook to annotate my textbooks and iAnnotate on my iPad. I can't figure out how to transfer my highlighting from the iPad to Macbook and vice versa. My textbooks are stored on Dropbox and when I open the textbooks from Dropbox on my computer after highlighting them on the iPad they appear unhighlighted.

    At some point I figured out a trick to solve this but for the life of me I can't remember how I did it now. Please help. I need a quick way to make it easier for me to cover my weekly readings without spending too much time trying to figure this out.

    I'm also open for suggestions if there are better apps out there than Skim and iAnnonate.


  2. onekerato macrumors regular

    Jun 6, 2011
    Skim on Mac and iAnnotate on iPad don't play well together. Here's why:

    (1) iAnnotate can sync changes back to Dropbox but it throws a fit if the PDF on Dropbox is older than the version it last synced or downloaded. It's response is to put your newly marked up PDF into a conflicted folder and sync breaks. If you want to use iAnnotate, you should try to use it exclusively for PDF annotations, and not edit the PDF on your Mac. Alternatively, re-download the modified PDF from Dropbox into iAnnotate before marking it up. Either way, the special precautions means iAnnotate is not really ideal for annotating seamlessly on Mac and iPad.

    (2) Skim stores it's annotations in a custom format, in the extended attributes of a PDF file. These annotations are not visible to other apps that open PDFs such as iAnnotate. Unfortunately, when Skim saves these annotations, it also changes the file modification date of the PDF. In turn, this causes an app like iAnnotate to throw a fit because it thinks its copy of the PDF is stale. (You can export flattened annotations into PDF from Skim but this is not really "sync" i.e. it's another PDF.) AFAIK, no iPad app can read Skim annotations. [This is a shame because Skim annotations are quite lightweight and save quickly. In contrast, when you change annotations in any other PDF editor, every page of the entire PDF has to be rewritten to disk. IF Skim was designed such that it didn't change the modification date of the PDF, and kept all the annotations confined to a .skim file, and IF we had an iPad app that could read & save to the .skim file and leave the PDF untouched, that would work beautifully for annotating even very large PDFs on Mac and iPad.]

    Instead, try this:

    (1) for annotating PDFs, this keeps the annotations embedded in the PDF. When any iPad app picks up such a PDF from Dropbox, it will see the annotations made in

    (2) Use PDF Expert (or iAnnotate) to sync the folder where the PDF is stored to your iPad. Before opening the PDF for editing, always "pull to refresh" on the folder to make sure you have the latest version from the Mac. When you finish editing, PDF Expert will automatically upload the annotated copy. The step to remember is to sync the folder in PDF Expert before you start editing the PDF. (And make sure Preview doesn't have the PDF open when PDF Expert tries to upload it. Else, it'll create get a conflicted, timestamped copy of the PDF instead.)

    (3) The PDF annotations made by or PDF Expert will be fully visible and editable in each other.
  3. Tissue Paper thread starter macrumors regular

    Jun 18, 2012

    Thank you for the tips. I followed the first part of your suggestion, when I highlighted using Preview, I was able to see my own highlighting in Dropbox even but the thing I was bugged down about is that it took about 3 minutes to upload my highlights from Preview to Dropbox and I only highlighted the title. I wonder how long it will take if I highlight a whole chapter. Does the file grow in size as I highlight?

    I haven't added PDF Expert yet. I don't mind paying the hefty price tag if I knew it was going to be a really good investment. I can't believe it's this complicated to transfer annotations back and forth between the two devices :/

    Do you suggest I remove my textbooks from Dropbox? It seems if I highlight locally it could be better but I don't see how I can sync the data later to the iPad unless there's some kind of app that's available on both that does the syncing.

    With all the hundreds of apps out there, no one came up with an easier way? lol

  4. onekerato, Jan 31, 2014
    Last edited: Jan 31, 2014

    onekerato macrumors regular

    Jun 6, 2011
    It took 3 minutes to upload because the entire PDF must be uploaded when you make annotations, and not just the "annotations" part. If your PDF is 100MB in size, then every time you save, Dropbox sees it as a new file of 100MB which must be uploaded and the older one deleted on its servers. [This is different than when you say update a keynote file, and because keynote files are really a folder on disk - only the parts that changed need to be updated on Dropbox and thus it's much faster.]

    The PDF doesn't grow much in size because of annotations, it's just that the uploading of entire PDF again and again takes a lot of time.

    Yep, I sync over the local wifi network for speed. I run a WebDAV server on my iMac using Apple's Server app ($20) and then connect from PDF Expert to sync a folder of PDFs on this server. Sync is quite fast over Wifi (802.11n wifi network speeds are 80Mbps+ whereas my internet connection is only 2Mbps, but even worse, a lot more apps want to claim that limited internet bandwidth.) You can also run your own WebDAV server using "WebMon" app ($25) or configure Apache yourself.

    Instead of jumping into PDF Expert, try their free app "Documents" by Readdle. It supports sync of folders too and highlight annotations on PDFs, so you should be able to thoroughly test out the workflow. Even iAnnotate supports WebDAV folders but I run into "404 not found" errors during sync in the latest iAnnotate so I prefer to stick with PDF Expert for now.
  5. augustya macrumors 68020


    Feb 17, 2012
    Where to find this it is not listed on the APP Store ?And there is no website with this name ? Where to find this APP ?
  6. ApfelKuchen macrumors 68030

    Aug 28, 2012
    Between the coasts
    Preview is part of OS X - check your Applications folder.
  7. augustya, Feb 1, 2014
    Last edited: Feb 1, 2014

    augustya macrumors 68020


    Feb 17, 2012
    Oh Ok ! with Preview did he mean the, Preview in MAC oh ok !
  8. Natekhsirv, Feb 1, 2014
    Last edited: Feb 1, 2014

    Natekhsirv macrumors newbie

    Feb 22, 2013

    After days of research i have concluded that the best pdf annotating app for iPad is PDFExpert 5 (updated in December, with multi user editing functions on the fly and ability to embed sound notes in pdfs!!!!).I use that for my med school books.The books are synced instantly to iCloud .gOOD READER doesn't sync bookmarks to my huge chagrin and iAnnotate isn't as feature rich as PDFExpert 5 .Never use dropbox sync for pdf sync on iDevices because that sync will end with app closure(within 15 minutes of your closing the app);instead use the iCloud functionality because iCloud continues to work in background and syncs without fail always.Moreover unlike Dropbox only th annotations get synced which run only in some kilobytes.For e.g. even for multi MB Sound files embedded into PDFexpert iCloud takes less than a minute to sync across my iHone and iMac

    On my iMac I have placed the iCloud folder of PDF Expert files in dock for easy access(Seescreenshot) .See accompanying screenshots (its in Library>MobileDocuments> 3L68KQB4HG~com~readdle~CommonDocuments) my dock permanently

    on my iMac i open the pdfs from this dock ickoud folder and annotate using whatever app(PDFPen/adobe/pREVBIEW)and the annotations are immediately synced to PDFExpert5.Like magic

    Hope it helps

    Attached Files:

  9. Tissue Paper thread starter macrumors regular

    Jun 18, 2012
    Onekerato, thank you! I downloaded Documents earlier. Will try it tomorrow at work!

    Augustya, I was like you at one point and thought Preview was at the app store hehe. It's already in your Mac!

    Nate, thanks! This sounds interesting but can I ask if it's possible to turn iCloud only for that particular folder? For some reason I don't feel comfortable turning iCloud for everything or for all my folders. Second question is, can I ask you to briefly explain how to set it up? :]
  10. onekerato macrumors regular

    Jun 6, 2011
    Your observation regarding iCloud sync versus Dropbox sync intrigued me...

    I tested iCloud sync in PDF Expert, and this is how I set up the experiment: a 20 MB PDF was synced to 2 iPads, and also opened the ~/Library/Mobile Documents/3L68KQB4HG~com~readdle~CommonDocuments folder on my Mac. I confirmed that the 20MB PDF exists on all 3 devices (2 iPads and the Mac.) Then drew a simple circle annotation on 1st page of PDF using and had to wait 10 minutes for the annotation to show up on either iPad. Similarly, when I made an annotation in PDF Expert 5 on the iPad, I could see on the Mac that PDF file size dropped to 0 and then the PDF file was downloaded again (a file progress bar animation os visible.) Clearly, it's not only the annotations but the entire PDF that is written to iCloud and back down to iPads.

    Furthermore, background sync of iCloud documents may or may not occur automatically. Apple does not guarantee that PDF Expert 5 will be able to sync (iCloud or otherwise) in the background, i.e. it depends on iOS 7's kindness as described here:

    The takeaway is: iCloud sync in PDF Expert behaves quite similarly to Dropbox sync. Both require fast internet access to work well because the entire PDF must sync back and forth. That is why I prefer running a WebDAV server on the local network for fast sync of large PDFs between Macs and iPads.
  11. Tissue Paper thread starter macrumors regular

    Jun 18, 2012
    Onekerato, I'm glad you tested it out because I wasn't able to. As it seems, my computer does not have "mobile documents". It was too complicated to set up an alias or create one from scratch so I just ended up purchasing PDF Expert and sent the PDF with annotations with Dropbox. IT took a bit to upload but it's doable I guess.

    The other solution is to annotate all textbooks and keep them on the iPad without transferring anything to the computer. Sort of like treating the iPad like an actual book and refrain from doing any highlighting on the Mac!
  12. onekerato macrumors regular

    Jun 6, 2011
    Got confirmation from Readdle support that indeed, the entire PDF is synced back and forth via iCloud, and there's no provision to sync annotations alone.

    BTW, to open your Mobile Documents folder on the Mac, switch to Finder, then hit SHFT CMD G, then enter "~/Library/Mobile Documents/". The title bar of Finder window confirms that you've reached "iCloud" :)

    To create an alias, just right click on a file/folder, and hit "Make Alias". Then rename/drag that newly created alias to the Desktop or anywhere else.
  13. des1303 macrumors newbie

    Jun 29, 2014

    Thank you for your very helpful posts!

    I tested Documents + Preview and annotations worked perfectly in both directions (I used FTP for easier testing, not WebDAV). I'd now like to setup PDF-Expert + Preview + WebDAV (Webmon), had a couple of questions.

    - After sync, are all the PDFs available offline view / edit on the iPad?
    - At next sync, will all changes be transferred (in both directions, assuming no conflict)?
    - Does WebDAV provide a generally useful way to get at Mac files from iPad?

  14. onekerato macrumors regular

    Jun 6, 2011
    I use the WebDAV sharing built into OS X Mavericks server. And I use OmniPresence app to sync folders across 3 Macs using this WebDAV server. Works very well. I added PDF Expert into this mix, and it handled sync of PDFs to & from a folder quite well. Yes, you can modify PDFs on either the iPad or Mac (one at a time) and changes are synced

    While many iPad "document" apps support logging into a WebDAV shared folder, it's tedious to remember to keep all important/latest files in that special WebDAV folder. Instead, you can use an app like Files Connect to log into your Mac and walk through all the folders on your Mac. For quick transfers from Mac to iPad, I usually use DropCopy (wireless, transfer single file) or PhoneView (wired, transfer folders).

    All that said, I now prefer to annotate PDFs on Evernote for Mac because (1) I like Evernote's choices of bold-pink-with-heavy-white-outline appearance of text notes and it stands out very well against text on the PDF page; (2) Evernote automatically inserts a helpful annotation summary at beginning of PDF; and (3) I now know where all my PDFs are and they're quickly searchable.

    I still like using a retina iPad to skim through PDFs but I prefer to do detailed PDF mark up in Evernote for Mac.


Share This Page