From deep in the archives (4 years late!), filed under “things I built but never posted on my web site”:

When a browser uses a web font but doesn’t have an italic or bold variation available, it will attempt to fake it! This is also known as font-synthesis. For some people (including me) this can be hard to detect visually.

faux-pas is a project to help detect this behavior so that you can fix it!

• npm install fg-faux-pas and include the script in your build. Or use the Bookmarklet!
• Demo (includes the Bookmarklet!) and Test Page
• View on: GitHub or npm
• Retweet

node-faux-pas is a project to run faux-pas on the command line:

• npm install -g node-faux-pas
• e.g. fauxpas https://www.zachleat.com/
• View on GitHub or npm
• Retweet