This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Incorrect subpixel rendering iin FF 19.0.2

  • 3 replies
  • 11 have this problem
  • 8 views
  • Last reply by johndoe678

more options

In many situations FF does not correctly display subpixel rendering. It appears as if the color one one side of a leg is assigned also assigned to the adjacent pixel of the leg. For a font leg only one pixel wide, there is no black portion of the leg, only the color which should be on the side. See http://tinypic.com/r/2rx6zax/6 or for a screen capture showing the problem. In the screenshot notice that the "l" in "baseline" is completely yellow.

The problem occurs frequently, on a seemingly random basis. Each line of text is affected individually. In the screenshot, the top three lines are affected; the bottom line is not affected. Selecting any text within an affected line will clear the problem for the entire line. As I scroll through a long page, lines that approach the top of the window will often become affected.

No other browser has this problem on the displayed pages. No other application has this problem. The problem is reproduced on a variety of sites. This site, support.mozilla.org shows the problem, but just for the text in the text entry boxes, though. The NewYork Times and slashdot are frequent problem sites. Other sites seem immune. I suspect it has something to do with how the text is packaged within the HTML for the page.

I am running Windows 7 (64 bit), and to the best of my knowledge, I have the latest version of all video drivers. My monitor is a Dell U2410. Turning off clear type or turning off font smoothing obviously eliminates the problem, but only by eliminating sub pixel rendering, making the fonts are more difficult to read. Interestingly, just activating the "ClearType Text Tuner" window, clears up the problem for the currently displayed text. Other actions besides selecting text in the line will also clear the problem.

I am able to reproduce the problem on a nearly a daily basis. I will be happy to provide further information if requested.

Question: Is there a solution to this situation short of disabling subpixel rendering?

In many situations FF does not correctly display subpixel rendering. It appears as if the color one one side of a leg is assigned also assigned to the adjacent pixel of the leg. For a font leg only one pixel wide, there is no black portion of the leg, only the color which should be on the side. See http://tinypic.com/r/2rx6zax/6 or for a screen capture showing the problem. In the screenshot notice that the "l" in "baseline" is completely yellow. The problem occurs frequently, on a seemingly random basis. Each line of text is affected individually. In the screenshot, the top three lines are affected; the bottom line is not affected. Selecting any text within an affected line will clear the problem for the entire line. As I scroll through a long page, lines that approach the top of the window will often become affected. No other browser has this problem on the displayed pages. No other application has this problem. The problem is reproduced on a variety of sites. This site, support.mozilla.org shows the problem, but just for the text in the text entry boxes, though. The NewYork Times and slashdot are frequent problem sites. Other sites seem immune. I suspect it has something to do with how the text is packaged within the HTML for the page. I am running Windows 7 (64 bit), and to the best of my knowledge, I have the latest version of all video drivers. My monitor is a Dell U2410. Turning off clear type or turning off font smoothing obviously eliminates the problem, but only by eliminating sub pixel rendering, making the fonts are more difficult to read. Interestingly, just activating the "ClearType Text Tuner" window, clears up the problem for the currently displayed text. Other actions besides selecting text in the line will also clear the problem. I am able to reproduce the problem on a nearly a daily basis. I will be happy to provide further information if requested. Question: Is there a solution to this situation short of disabling subpixel rendering?

All Replies (3)

more options

Have you tried changing some of the gfx settings in the about:config page? I changed some of them and fonts look very good with Firefox for me.

  • gfx.color_management.enablev4 - set to true
  • gfx.color_management.mode - set to 1
  • gfx.use_text_smoothing_setting - set to true
more options

Try to disable hardware acceleration in Firefox.

more options