Do you have an Nvidia graphics card? Mozilla has disabled hardware acceleration for certain Nvidia driver software on Windows 10, and this reduces Firefox's ability to smooth fonts. Hopefully this will be fixed soon, but I am not familiar with when Nvidia might release an update.

Related thread: Firefox is messing up the fonts.

If it's NOT Nvidia, hmm, we'll have lots more questions.

Yeah it's an Nvidia card. Sorry about the duplicate post.

And thank you for the quick reply :)

I'm having similar issues. Upgraded to Windows 10 and FF 40 and font rendering is terrible, however I do not have an Nvidia GPU. Instead I have an AMD R9 380.

Hi retep998, could you check the Graphics section of the support information page to see what it lists for your graphics card. Either:

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

Scroll down to the Graphics section, then select and copy the table and paste it into a reply.

Adapter Description AMD Radeon (TM) R9 380 Series Adapter Drivers aticfx64 aticfx64 aticfx64 amdxc64 aticfx32 aticfx32 aticfx32 amdxc32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64 Adapter RAM 4095 Asynchronous Pan/Zoom none ClearType Parameters Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 200 Device ID 0x6939 Direct2D Enabled Blocked for your graphics card because of unresolved driver issues. DirectWrite Enabled false (10.0.10240.16390) Driver Date 7-15-2015 Driver Version 15.200.1046.2 GPU #2 Active false GPU Accelerated Windows 1/1 Direct3D 11 (OMTC) Subsys ID 200f1787 Supports Hardware H264 Decoding true Vendor ID 0x1002 WebGL Renderer Google Inc. -- ANGLE (AMD Radeon (TM) R9 380 Series Direct3D11 vs_5_0 ps_5_0) windowLayerManagerRemote true AzureCanvasBackend skia AzureContentBackend cairo AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0

Well unfortunately:

retep998 said

Direct2D Enabled Blocked for your graphics card because of unresolved driver issues.

I don't know what those specific issues are, but hopefully a fix will come along in a Windows update or in a change to Firefox.

Any known fixes/updates for this? :(

Hi markpaulk, I notice you started a new question so I'll check your situation over there: https://support.mozilla.org/questions/1097913

jscher2000 said

Hi markpaulk, I notice you started a new question so I'll check your situation over there: https://support.mozilla.org/questions/1097913

So after going mad and trying just about everything, the problem seems to have finally been resolved. A massive update to Windows 10 (several restarts, big black screen showing update progress after each reboot) was released recently and the problems have gone away! Hoorah. Looks like it was a problem on Microsoft's end, not Mozilla's :). Thanks.