Open Bug 1506953 Opened 11 months ago Updated 4 months ago

Blurry PDF in built-in viewer


(Firefox :: PDF Viewer, defect, P2)

63 Branch





(Reporter: xalilolih, Unassigned, NeedInfo)




(2 files)

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Firefox/60.0

Steps to reproduce:

Load an arbitrary PDF file. OS:MacOS Mojave. Firefox version:63.0.1

Actual results:

The text and images are blurry compared to an external PDF viewer (e.g. SKIM)

The pdf on the left was grabbed from Firefox's own internal PDF viewer; the right image was grabbed from SKIM.

Expected results:

PDFs should be crisp.
Component: Untriaged → PDF Viewer
I have the same problem on Ubuntu 18. I've experienced the issue only for a day or two (and I open PDFs all the time). The same PDF files are shown without blur in chrome on the same system. The blur is similar to what xalilolih showed. Example of an PDF that gets blurred for me:

Is it blurry for all PDFs? If not can you link to or attach a PDF that has issues?
Flags: needinfo?(xalilolih)

I have had this issue for months with every version of Firefox that I've tried (standard, beta, and nightly). It seems to be related to using Firefox on a high DPI display (Retina Macbooks).

To reproduce, open any PDF in the built-in PDF viewer using Firefox for Mac with a high DPI display. The PDF will appear blurry. Opening the same PDF in either Chrome or Safari will result in a crisp, clear image.

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Firefox/60.0
OS: macOS Mojave 10.14.2
Model: MacBook Air (Retina, 13-inch, 2018)
Graphics: Intel UHD Graphics 617 1536 MB
Firefox Version: 65.0b11


Duplicate of this bug: 1532330
Priority: -- → P2

I have just recently encountered the blurry font rendering issue on Windows 10 Home 64-bit, Firefox Nightly 69.0a1 (2019-06-13).

PDF of interest:

I'm not sure how to attach the PDF, in case it gets changed.

Screenshot showing side-by-side Firefox and Acrobat Reader DC:

Attached file Comment 5: PDF example

In reference to comment 5, this PDF attachment has blurry font rendering in Firefox, but is not blurry when viewed in Acrobat Reader DC.

This is on a Windows 10 Home 64-bit laptop.

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