How many fonts are available in the web browser?

[lgillis]

Thanks to JavaScript, my Firefox makes a selection of more than 250 fonts I've installed available to websites I don't know, so they can provide me with a customized user experience. Isn't that nice?

• https://browserleaks.com/fonts "Font fingerprinting techniques rely on measuring the dimensions of HTML elements filled with text or single Unicode glyphs. However, font rendering in web browsers can be affected by multiple factors, leading to subtle differences in these measurements."

This applies to any JavaScript-capable browser with JavaScript enabled. Even if you only select use custom fonts in the configuration.