How to type Capital Psi
To type Capital Psi (Ψ), press Alt + 936 on Windows, holding Alt while typing the digits on the numeric keypad, or write Ψ in HTML. On any system you can copy it from this page, or enter its codepoint U+03A8 directly: Ctrl+Shift+U then 03a8 on Linux, or 03a8 then Alt+X in Microsoft Word.
Greek Capital Letter Psi
- Copy it
- Unicode
- U+03A8
- Windows
- Alt + 936 needs regedit
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 936 | Above 255, so Windows will not accept it as typed. Copy the character instead. |
| Mac | N/A | Press the keys together. |
| HTML | Ψ | Paste this into HTML source. |
| Unicode | U+03A8 | GREEK CAPITAL LETTER PSI |
Other greek symbols
Ψ lives in the Greek and Coptic block (U+0370-U+03FF), the Greek alphabet, used throughout mathematics and the sciences. Within Unicode it is classified as Lu, an uppercase letter. It has a lowercase counterpart and changes under case conversion. Its bidirectional class makes it left-to-right.
Its lowercase counterpart is ψ (U+03C8). They are separate codepoints, so a byte comparison treats them as different characters even though a case-insensitive search does not.
What Capital Psi is used for
In mathematical notation Ψ is a variable: it stands for a quantity rather than acting on one, so an equation treats it the way it treats x, and the spacing around it is the spacing around a letter. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\mupPsi$ in LaTeX, in maths mode rather than in a sentence.
The command is \mupPsi rather than the \Psi most people reach for, and the difference is not cosmetic: mup is unicode-math for maths, upright, and this codepoint is the upright letter. Plain LaTeX's short command gives the sloped math-italic letter, which is a different character with a different codepoint. Copying Ψ into an equation gets you the upright one.
Ψ is a letter before it is a symbol, and on the Greek keyboard layout it is simply Shift and C: the key your keycap already calls C. That is the route when you are typing Greek rather than reaching for one character. How to type Greek on a keyboard has the whole map.
How Capital Psi behaves in software
Ψ is East Asian Ambiguous: one column in a Western locale and two in a CJK one. That is why a table that lines up on your machine can break on somebody else's, with no change to the text at all. It is a left-to-right character, so it holds that direction even inside a right-to-left paragraph.
Every way to write Capital Psi
| Form | Value |
|---|---|
| Codepoint | U+03A8 |
| Decimal | 936 |
| UTF-8 bytes | CE A8 |
| UTF-16 bytes | 03 A8 |
| HTML entity | Ψ |
| HTML numeric | Ψ or Ψ |
| CSS | \03A8 |
| JavaScript | \u03A8 |
| Python | \u03A8 |
| URL-encoded | %CE%A8 |
| LaTeX, in maths mode | $\mupPsi$ |
| SVG | 03A8.svg · (SIL Open Font License) |
If Ψ arrives as Ψ
That is this exact character, undamaged: its two UTF-8 bytes CE A8 are being read one at a time as Windows-1252. The Latin-1 range is where this happens most, because it is the range every legacy system thought it already handled. Nothing is lost, and retyping will not help: the fix is at the reading end, which has to be told the text is UTF-8. An empty rectangle is the opposite complaint, and means the encoding is right and the font has no glyph for U+03A8.