DirectWrite text rendering survey

June 23rd, 2011 by John Daggett

Firefox 4.0 uses the DirectWrite text rendering API if it’s available on your Windows 7 machine. In order to get a better idea of the range of text rendering behavior that Windows 7 users are seeing, we’ve put together a small text rendering survey. The survey renders content using a variety of Cleartype settings and asks you to choose the rendering that looks most readable to you. For each question, there’s also a comment field so you can point out funny artifacts or anything that seems out-of-place to you.

If you’re using Firefox on a Windows 7 machine, please grab a tasty beverage and take a few minutes to help us out!


  1. Download the latest nightly build.
  2. Download the zipfile containing the survey.
  3. Open the readme.html file.
  4. Read through the instructions and click on the link to run the survey.
  5. Click ‘Allow’ in the security dialog to allow the script to modify browser prefs (this is needed to render with various Cleartype settings).
  6. Run through the survey renderings, selecting what looks best to you.
  7. Submit the results.

The submitted results contain the sample renderings and your selections along with basic info about your system Cleartype parameter settings, plus your name and email if you supply it.

Thanks very much for your help with this!

14 Responses to “DirectWrite text rendering survey”

  1. Antwan Says:

    DW rendering is so crispy and ugly… I disabled it to keep GDI+Freetype rendering (with GDI++/GDIPP hack tools).

  2. Jarkko Seppälä Says:

    My eyes are bleeding! Have to do this test couple of times. Where i can compare my own test results? Interested to see how much my own results differs from other.

    Who the hell did this test?

    Methods of science
    Monkeys so full of winning
    Destined to be fast

    What? 😀

  3. jdaggett Says:

    That’s a haiku from one of the Javascript team guys!

    I’ll try and put together a page with the results once we’ve collected a good sample. Thanks for running through those!

  4. Fanolian Says:

    Will there be surveys for language scripts other than Latins? Different scripts may perform best in different rendering modes.

  5. Ruslan Rudenko Says:

    Done! I hope that it will help to improve current Firefox text rendering 🙂

  6. Robert Says:

    Done.Would be intresting to see the results some day.

  7. Zsolt Torok Says:

    I hope it will help the team, and i’m also curious for the results.

  8. xeon Says:

    I have hardware acceleration disabled in ff4 /win7.. just so I don’t have the bad font rendering.. so that will be default crispy text with cleartype settings ..whole pixel.

  9. Samson Says:

    Nope. I purposefully installed Firefox 6 because this DW rendering stuff is absolute crap. GDI readable text FTW.

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  11. patrick Says:

    just did the survey, i’d love to see the results. right now i disable d2d in all mozilla apps i use but it would be great to have a rendering that just works.

    hw-accel ftw ^^

  12. Alexander Says:

    Done that test.
    Commented as possibly

  13. Martin Says:

    Hey 😉
    I’ve got a noob question…
    If I browse on Firefox 4 on a Mac OSX (let say Lion as an example), would I see the DirectWrite rendering in FF4 ?
    Does FF4 include his own rendering engine that always run over the OS font rendering setting ?
    Thanks a lot for your answer

  14. John Daggett Says:

    @Martin, Firefox always uses the OS font rendering API’s. So on versions of Windows that support DirectWrite you’ll see DirectWrite rendering, GDI rendering otherwise. On OSX you’ll see CoreGraphics rendering, on Linux FreeType rendering. Firefox uses the HarfBuzz shaping library on all platforms, this determines which glyphs are selected and where they are placed, but the actual glyph rasterization is done by an OS library.