How Stylish Name Generators Actually Work (Unicode Explained)
Stylish name generators do not really change your font. They swap each letter for a different Unicode character that looks like a styled version of that letter. Because these characters are part of the universal Unicode standard, they display correctly across apps and devices.
Why some fonts break on certain apps
If a platform’s font does not include a particular Unicode character, it shows a box instead. That is why a style may look perfect on one app and broken on another.