Why fancy text shows as boxes
Your phone draws text using fonts installed on it. When a character is missing from every font, you see a “tofu” box ▯ or a question mark. Styled text you copy here is exactly the same code points your friends receive; whether they see 𝓝𝓸𝓿𝓪 or ▯▯▯▯ depends on their device.
Mathematical letters (bold, italic, script, gothic, double-struck) were added in Unicode 3.1 in 2001 and are now in the system fonts of iOS, Android, Windows and macOS, so they are the safest styled letters. Look-alike borrowings from rare scripts — mirrored and upside-down capitals — are the least safe.
Questions
How does the checker decide if a character is safe?
It looks up the Unicode block of each character and rates the block by whether the default fonts on current iOS, Android, Windows and macOS include it. It cannot see the fonts on a specific phone, so treat “hit-and-miss” as “test on a second device”.
Why is my Instagram bio “too long” when it looks short?
Combining marks (strikethrough, underline, zalgo) and invisible characters each count as a character. The checker shows the count Instagram, TikTok and Discord use (code points) and X’s weighted count.
What are invisible characters?
Characters like the zero-width space (U+200B) or Hangul filler (U+3164) take up no visible space. People use them for “blank” names, but many platforms strip or block them.
Can I turn fancy text back into normal text?
Yes — press “Make plain”. It maps bold, script, gothic, bubble, wide, small caps, flipped and mirrored letters back to plain letters and removes combining marks.