Greek letters · U+03BB

λLambda symbol

λ is the Lambda character. It is text, not a picture — it takes the colour of the type around it and pastes into anything.

How to type it
Unicode
U+03BB
Alt code
Alt+955
HTML
λ
Unicode name
Greek Small Letter Lamda
U+03BBYour font
λ

01 — Origin

Where the Lambda symbol comes from

Lambda earned its modern fame twice. In physics it has denoted wavelength since the nineteenth century; in computing it comes from Alonzo Church’s lambda calculus of the 1930s, where the choice of letter was close to accidental — a typesetting compromise for a caret over a variable.

Wavelength in optics, decay constant in physics, anonymous functions in half the programming languages in use, and the name of AWS Lambda after them.

Worth knowing
The capital Λ is a different character and mostly means something else entirely — the cosmological constant in physics, and a logical AND in some notations.

02 — Codes

Lambda symbol codes

Copy whichever form your tool expects. The character behind them does not change.

03 — How to type

How to type λ on any keyboard

Four ways, depending on what you are working in.

Windows
Hold Alt and type 955 on the numeric keypad, then release. Without a keypad, use the Character Map app (search “charmap”).
Mac
Press Control + Command + Space to open the character viewer, then search “lambda”. Double-click to insert.
Phone
There is no shortcut on a phone keyboard. Tap the symbol at the top of this page, then long-press in any text field and choose Paste.
Web and code
In HTML write λ or λ. In CSS content: "\03BB". Make sure the page is served as UTF-8 and the raw character works too.

04 — Font support

Will λ actually show up?

We checked 147 fonts installed on a normal machine and counted how many of them contain this character. A symbol missing from a font is drawn as an empty box — the text is still correct, it just cannot be drawn.

86% 126 of 147 fonts

Safe in most places. Common fonts have it. Older or decorative fonts sometimes do not, so a fallback font will kick in.

05 — Similar

Symbols people confuse with λ

Close enough to be mistaken for it, and still a different code point every time.

06 — Related

Other Greek letters used as symbols

Relatives of this character. Each has its own page with origin, typing and font coverage.

Σ Sigma symbolIn 86% of system fonts Ω Omega symbolIn 86% of system fonts α Alpha symbolIn 86% of system fonts β Beta symbolIn 86% of system fonts Δ Delta symbolIn 86% of system fonts

07 — Same block

Greek letters

Alpha to omega, the alphabet science borrowed.

All greek letters →

08 — FAQ

Lambda symbol — questions

How do I type the Lambda symbol?
On Windows hold Alt and type 955 on the numeric keypad. On Mac open the character viewer with Control + Command + Space and search “Lambda”. Or just tap the symbol on this page — it goes straight to your clipboard.
What is the HTML code for λ?
Write it as λ or λ in HTML, \03BB in CSS content, and \u03BB in JavaScript. All four produce the same character.
Is λ an emoji?
No. λ is a text character — it takes the colour of the text around it and works in usernames, filenames and documents. An emoji is replaced by a colour picture and is sometimes stripped by forms and systems.
Why does λ show as a box on some devices?
Because that font has no drawing for this character. We checked 147 fonts on a normal machine and 126 of them include it. The character itself is always correct; only the drawing is missing.