What's your computer system and Firefox version?

Please explain the problem in detail. Is this all the time? On web pages? Which ones?

Start Firefox in Safe Mode {web link} by holding down the <Shift> (Mac=Options) key, and then starting Firefox.

A small dialog should appear. Click Start In Safe Mode (not Refresh). Is the problem still there?

The spacing between both letters and words when typing is wider than what appears here and does not conform to normal usage. For some reason I am unable to replicate the problem in this reply and consider this message to be the desired norm. Additionally, I am unable to change font styles. Quite a nuisance to say the least....

As a test, you should fiddle around with changing the Font + Colors by going here ; about:preferences#content. Is this occurrence of no ordinary timeline? Just completely random?

This could be related with the recent switch in Firefox 52+ from Cairo to Skia for canvas/content rendering.

Firefox 52+ has changed from Cairo to Skia for canvas/content rendering.

• https://www.mozilla.org/en-US/firefox/52.0/releasenotes/
• When not using Direct2D on Windows, Skia is used for content rendering

You can modify these gfx.*.azure.backends prefs on the about:config page to revert to the old font rendering swap the skia,cairo order to cairo,skia or remove the skia and leave cairo.

• gfx.canvas.azure.backends = direct2d1.1,cairo,skia
• gfx.content.azure.backends = direct2d1.1,cairo,skia

You can open the about:config page via the location/address bar.

You can accept the warning and click "I'll be careful" to continue.

• http://kb.mozillazine.org/about:config