5 Stars. This add-on is the best option in Firefox Quantum for correcting the flawed design of websites that feature barely visible grey text. An alternate add-on with the same objective exists, but it is quite buggy in post-57 Firefox.

The introduction of the blacklist feature in version 1.3.1 further cements Font Contrast as the best add-on of its kind. Thanks to the developer for the response to my previous review, in which I had requested this feature.

With regard to the comment by Joy, below:

The icon in the address bar can be hidden (right-click it and select appropriately). Thereafter, right-click the Firefox titlebar, select "Customize..." and drag the Font Contrast icon among your other add-ons. If you ever restart your Firefox with add-ons disabled, you'll have to redo the part about hiding the address bar icon, as doing so will restore the icon. Ultimately, though, what you want is easily done.

Does what it says, therefore very useful. Thank you!

Ooh thank god, I can't read most websites because the text is too light! Please, keep this addon up to date, it's really needed.

Back to 5*. Tried it on a few pages and it seems to be working. Thanks. Original Review: It worked great when I first installed it but then the icon didn't activate it anymore. Even online reads that were just text no longer turned black. Tried having it always on. Then the problem became it darkened white on black text to black and that seemed to be unaffected by the slider setting. After days of trying various things I uninstalled and plan to re-install. Hope it wasn't update that caused the problem. If it was I'll disable and watch for next update because I really 5* liked this when it worked. Thanks for developing this to help those of us who detest grey text and a bigger thanks on behalf of those who are vision impaired.

good

Essential add-on, even if one uses Stylus and particular userstyles.
Would it be possible to add a feature such as making letter a little bit "bolder" ?
In some cases, even with contrast added, letters look very thin ... (I guess it is a choice of web designers similar to the light colors on white background ...)
Have a nice day

works just fine on Quantum, only one little problem is that it seems to want to be on when I don't want it to be on, otherwise it is just what I wanted

Letting the punishment fit the crime department: The idiots who have been pushing low contrast type should be put in a prison with ones who write novels by pasting letters cut from magazines onto pages (think ransom notes), the ones who stopped using words on signs in favor of hieroglyphs, the ones who make the power switch almost impossible to find on electrical appliances, and doctors who write important medical information in an indecipherable scrawl, and they should all be forced to use each other's annoying work. Review by vdicarlo: Font Contrast Fix has unfortunately become an essential extension. It does the job, and I am grateful to Fushko for giving it to us. Suggestions: global default and settings by site and page, apply fix to text boxes like this one that are currently unaffected while you are working in them.

3/22/2018 - I do not perceive any effect when used on my Opensuse Linux Leap 42.3 XFCE box with Firefox 64 bit version 52.7.2 Seems like this happened some time ago. I have tried uninstalling and reinstalling. Perhaps you could post or send me the url of a site where its effect should be very noticable. I would be willing to try to troubleshoot. This extension was too useful to lose. My domain is dicarlolaw top level com where I get mail at my username above.

I think it's better to make 2 modes:
1. Remember the position of the button for each of the site visited.
2. Don't remember (mode as work now).