Unicode bold characters are not displayed in mobile browser or app

Question

I have posted an article to facebook page which contains bold unicode title which is displayed fine on desktop browser but when I open the facebook app or chrome browser in mobile, the unicode is displayed as sqaure boxes.

Any idea why unicode isn't working on mobile app or browser?

Answer 1

In phones, unicode font sets vary from phone to phone, from year to year, from brand to brand, from browser to browser, from font to font.

An older and cheaper phone may have lots of missing unicode characters for memory's sake, or just because it uses a font that doesn't have bold characters/many emojis/fancy letters/arrows/obsolete Chinese characters...

Unicode is updated more or less once per year, and new characters are added to the standard.

Then, it's up to companies, like Google, Apple, Samsung etc. to keep up with the update and add new characters to the unicode fonts that are used in their devices.

So, it may work in one device, but may not (completely/partially) work in another.

It is generally safer to abstain from using infrequent unicode characters, such as rare emojis, bold letters, upside-down letters, strikethrough/underline markers.

If bold/underline etc. are not provided by the site itself (Facebook) via HTML, CSS and appropriate fonts, then there is no guarantee at all that people will see the same thing in different devices.