Iota — ι Greek Letter Symbol
ι
Iota — ι / Ι
9th letter of the Greek alphabet · pronounced /aɪˈoʊtə/
MathematicsPhysicsComputer Science
Copy symbol
ι
Lowercase iota
Ι
Uppercase Iota
Technical reference
| Unicode (lowercase) | U+03B9 |
| Unicode (uppercase) | U+0399 |
| HTML entity | ι |
| HTML decimal | ι |
| LaTeX | \iota |
| Python / Unicode escape | \u03b9 |
| Alt code (Windows) | Alt + 953 |
Uses in science & engineering
Inclusion map (mathematics)
Denotes the inclusion or embedding of one set into another in topology and algebra.
\(\iota: A \hookrightarrow B\)
Index variable
Used as a summation index or iterator, especially in sequences and series.
\(\sum_{\iota=1}^{n} a_\iota\)
Unit vector (APL / programming)
In APL and some array languages, iota generates integer sequences.
\(\iota n = \{1, 2, \ldots, n\}\)
Slight quantity
“Not one iota” — the letter represents the smallest meaningful unit, used informally to indicate a tiny change.
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Related symbols
How to insert in applications
Windows
Best option: copy from this page.
Or press Win + . to open emoji & symbols panel.
Alt codes work only in Word/Notepad with NumLock on and English layout — not in browsers.
Or press Win + . to open emoji & symbols panel.
Alt codes work only in Word/Notepad with NumLock on and English layout — not in browsers.
macOS
Press ⌃⌘Space → Character Viewer → search “iota”
Microsoft Word
Type 03b9 then press Alt+X
Google Docs
Insert → Special characters → search by name
Excel
Insert → Symbol → Subset: Greek → select symbol
LaTeX
Use in math mode: $ … $
Python
Use Unicode escape or chr()
HTML / CSS
Use HTML entity or decimal code