I have a large pdf file and I was wondering how I could decrease the lag when scrolling.

I tried breaking the file into smaller sections (roughly 20 page chunks) but that didn't help. I'm thinking scrolling is so slow because each page is some sort of image.

Are there any other steps I can take to reduce the choppiness when scrolling?

  • 5
    Most of the answers I see to this question - both here and around the web - treat the problem as if it is the exception case. Eg ultra large pdf, low ram, slow disk, some funny kind of document compression, etc. This behavior is not the exception and can be widely repeated across pdfs of different sizes and compositions and across Macs of various speeds. My particular case is a mid-2011 Macbook Air with 4GB RAM, an ssd and
    – Matthew
    Jul 26, 2012 at 6:20

7 Answers 7


How is the PDF compressed? If it is black and white only, it may be using a compression method that leads to choppy behaviour.

I was recently dealing with a product manual that was a black and white only scan. It was compressed using JBIG2, and it stuttered enormously when scrolling, even on a top-of-the-line MacBook.

I opened the document in Adobe Acrobat, and recompressed it using ZIP, and the scrolling problem went away entirely.

If you have Acrobat Pro, the steps I took were: Open the file -> Save As -> "Optimised PDF" -> Change the "Monochrome Images" compression dropdown to "ZIP" -> Ok.

It does increase the size of the file (from 1.2 MB to 3 MB), but I can actually skim the document now.

I think it mostly boils down to the fact that JBIG2 is compute-intensive, and Most PDF applications don't render the document much ahead of the current page.

If you don't have Acrobat, and you can post the PDF, I can take a look at it for you.

  • My university offers Adobe Creative Suite Premium 5.5, so as soon as I can, I'll download Adobe Acrobat, and try this out.
    – Dante
    Dec 1, 2011 at 10:15
  • where do you find how the document was compressed?
    – derelict
    Jul 16, 2015 at 15:23
  • Not sure if the pdf was compressed, but saving as optimized (default settings) reduced file size from 1.5mb to 486kn.. choppy scrolling is gone. Thanks.
    – derelict
    Jul 16, 2015 at 15:56

What are the specifications of your Mac? If you have very little RAM, that might impact your system speed overall.

UPDATE According to your screen shot, this is a mid-2010 MacBook Pro with 4GB RAM. This is a fast computer with sufficient RAM for this task, so this is not the problem.

  • That might be it. Here's a screenshot of my current system specifications. cl.ly/360X3E2T240j3x2q3M2r
    – Dante
    Sep 30, 2011 at 21:35
  • My 470 upgrades to 8G and SSD, but using Preview to view a PDF file with lots of images, have the similar problem as @Andrew. For such PDF file, change to use Skim will be a bit improved.
    – kukoo
    Oct 1, 2011 at 3:44
  • @Wheat Williams. I'm starting to think it probably has something to do with the file itself--usually I don't get this sort of behavior even with my other, larger pdf files.
    – Dante
    Oct 1, 2011 at 5:28
  • I own macbook with 16gb RAM and SSD and some PDFs lags while scrolling (even in Chrome browser).
    – Kyslik
    Sep 29, 2015 at 13:53

Using an alternate PDF viewer, eg. Skim, might improve performance.

  • I tried it, and there was no substantial difference in the scrolling. Thanks for the suggestion though. I can definitely see this app coming in handy--just not for the reasons listed above.
    – Dante
    Sep 30, 2011 at 22:04
  • I have some eBooks with lots of images inside, usually I will use Skim instead of Preview to read those files. A bit improved.
    – kukoo
    Oct 1, 2011 at 3:45
  • It was, but I'm still having trouble scrolling. It probably has something to do with my pdf--it's strange behavior. I have a couple other textbook's that are thousands of pages long with images here and there, but I don't have the same problem when scrolling.
    – Dante
    Oct 1, 2011 at 4:55
  • Tbh as far as PDF readers go, preview is by far the fastest, simply because pdf support is built on a low level into os x.
    – Alexander
    Nov 30, 2011 at 7:16
  • @XAleXOwnZX - What do you mean by "built on a low level into os x"? It's just another OSX app that happens to be from Apple and included with the operating system. Low level doesn't apply in this case.
    – Matthew
    Jul 26, 2012 at 6:21

Adobe's Acrobat Reader DC is significantly faster at opening and displaying some 1500+, 250 MB+, vector graphics-heavy files than preview. While Preview requires about 20 seconds to load it's more or less instantaneous in Acrobat Reader.


More info to share besides @Fake Name's answer:

After exploring all the pdfs I have that suffer from stuttering in scrolling, they are all old PDFs (I guess, generated by latex in the process ps->pdf), which uses Postscript font types (e.g. Type3). And the fonts are shown blurry in Preview.app. (No matter how small the PDFs are, e.g. <10k. However, if you only have a few pages, say 3 pages, the scrolling stutters only the first time you reach that page or during a few seconds after opening the file.)

The Preview.app on Yosemite fails to deal with these fonts appropriately (rendering, smoothing). When opening them, any scrolling on the pages firstly visited will show stuttering, lags (not slightly, quite obvious and serious).

Alternative "Solution" (alleviating scrolling lags): in Preview.app, "Preferences" -> "PDF" tab -> uncheck "smooth text and line art". Then you will see significance improvement of scrolling performance. However, fonts are still shown blurry if not zooming in. One word, these fonts are no longer well supported after Yosemite. (Note that disable smoothing will give you really bad font rendering in other normal PDFs).

If I remember correctly, the old versions of OS X didn't have this problem; maybe certain functionalities of Preview.app have been removed, since new LaTeX typesetting systems no longer use these fonts any more (while you can still configure it and to use them). No idea why Apple meant to produce these troubles.


"Print to pdf" then open result in Preview again. It is a temporary fix or you could resave it this way for a permanent fix.

  • What sort of size savings does this provide on a 100 page PDF made of images? I have not found this to help with documents described here.
    – bmike
    Nov 22, 2012 at 20:29
  • Not sure why this answer has been so heavily downvoted. It actually worked very well to me!
    – Manlio
    Sep 16, 2014 at 20:18

You could hit the space-bar which will open Preview.app The file won't open with any Adobe program that way and won't lag.

Works great unless you have to edit the files for example, because you cannot achieve that with Preview.app.

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