PDFs and Preview — why so blurry?

Discussion in 'macOS Mojave (10.14)' started by epetrovski, Oct 5, 2018.

  1. epetrovski, Oct 5, 2018
    Last edited: Oct 5, 2018

    epetrovski macrumors newbie


    Aug 29, 2017
    Copenhagen, Denmark
    PDFs opened in the Preview app for Mac OS Mojave (10.14.0) are blurry. It's most visible when looking at text but lines and other graphics are blurry as well and it's worse the more you zoom out. I'm on a MacBook Pro (Retina, 13-inch, Mid 2014).

    Being able to render PDFs clearly is just such a basic task for a PDF viewer — which makes it all the more baffling why this has remained an issue for at least since the release of Mac OS High Sierra (https://forums.macrumors.com/threads/blurry-pdf-rendering-in-preview.2074669/).

    One weird thing I noticed is that a PDF opened in Quick Look is actually nice and crisp but the same PDF opened in the Preview app is still blurry:


    Of course, Google Chrome or any other PDF Viewer still renders PDFs nicely on Mac OS Mojave:


    Here's a close-up of the difference between Preview and Chrome:


    As others have noticed, PDFs viewed on iOS devices – e.g. via the Files app – are blurry as well. Reading a PDF on my iPad Pro has really become a pain. This apparently points towards PDFKit being the problem.

    Does anyone have a clue as to what is going on and why Apple is not addressing this?
  2. Ritsuka macrumors 6502a

    Sep 3, 2006
    Please report a bug on bugreport.apple.com , more bugs means someone at Apple hopefully will fix it sooner.
  3. niji Contributor


    Feb 9, 2003
    1 pdf's using Preview on a mac have never been rendered crisply as on windows
    2 pdf's using Adobe on a mac render better, however.

    its always been that way.
    i have wondered if the reason for this is apple is simply not paying some kind of patent fee to adobe in order to use apple's own tech

    since i don't use Chrome i haven't known about it rendering better in Chrome.

    but anyway, PDF rendering poorly on macs is not something new.
    not just on the screen but even when printed out.

    before apple came out with the app called Preview, apple rendered PDFs within Safari.
    Preview to me is simply a PDF management app. its horrendous.
  4. epetrovski, Oct 5, 2018
    Last edited: Oct 5, 2018

    epetrovski thread starter macrumors newbie


    Aug 29, 2017
    Copenhagen, Denmark
    I already have and so have others (https://forums.macrumors.com/threads/blurry-pdf-rendering-in-preview.2074669/#post-25186567). But Apple just seems to mark the issue as a duplicate and nothing happens.
    --- Post Merged, Oct 5, 2018 ---
    It might be true that rendering PDFs in Preview—and before that, Safari—has always been subpar but it's never been as bad as since Mac OS High Sierra.

    But what puzzles me the most is that even if it's simply a matter of Apple not being capable of producing a decent PDF reader then why is it that PDFs render much better when simply opened via Quick Look (selecting the file and pressing the space bar) rather than opening PDFs in the actual Preview app. Quick Look renders a PDF almost as nicely as Chrome does:

  5. Ritsuka macrumors 6502a

    Sep 3, 2006
    It's better in QuickLook because the window size is different than Preview, if you resize the Preview window you will find that it looks better sometimes, even a 2 px difference can improve the rendering.
  6. w4z macrumors newbie


    Jun 17, 2018
    i skipped high sierra caused by pdf related issues. i created a test file to compare text and geometry, i looked again today and all texts looks same, blurry text fixed for me

    converted texts are same with normal texts now
    test pdf; https://www.dropbox.com/s/ucv0i2gpcdlq7ah/macos_test_pdf.pdf?dl=1

    also a worse problem not fixed since high sierra
  7. epetrovski thread starter macrumors newbie


    Aug 29, 2017
    Copenhagen, Denmark
    Quick Look renders text clearly at virtually any size whereas Preview is blurry at anything < 200 % zoom or so.

    I'm starting to think that Preview applies some sort of smoothing to text and graphics and Quick Look doesn't. If this smoothing could just be disabled like in older versions of Preview, which had the "smooth text and line art" option, then Preview might be able to display PDFs without blur. What a treat that would be.
  8. Spectrum macrumors 65816


    Mar 23, 2005
    Never quite sure

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7 October 5, 2018