Underscore symbol

Click the underscore symbol below to copy it, then paste it anywhere — a username, a file name, a line of code or a blank in a form. The underscore (_) is the low line that sits on the baseline of the text, typed with Shift + hyphen on almost every keyboard. This page collects the plain underscore, its underline variants, and ready-made blanks, together with the underscore definition, its codes, and how it differs from a hyphen or a dash. (The name is sometimes typed as two words — under score symbol — but it means this same character.)

Fastest choice: the card above copies the standard underscore, ‘_’ (U+005F). The grid below adds the fullwidth and dashed forms, a combining underline, and ready-made blanks like ____.

Copy and paste underscore and low-line symbols

Each button copies one item. The combining low line (U+0332) is special: paste it right after a letter and it underlines that letter, like this: a̲. The spaced pair card copies _ _ exactly as shown, for handwriting-style blanks.

What is an underscore? Definition and meaning

Underscore definition: an underscore is a short horizontal line drawn at the baseline of the text — underneath where letters sit. To define underscore in one sentence: it is the character you get from Shift + hyphen, used where a space is not allowed or where a blank is needed. By definition underscores in the plural are simply two or more of the character in a row or in a text, and every underscores definition in a dictionary describes the same baseline line, together with a second job as a verb.

That second job explains the underscore meaning in ordinary writing. As a verb, underscoring means underlining a word for emphasis, and by extension stressing a point — “this underscores the problem” means the fact underlines it. On paper, the meaning underscoring carries is always “pay attention to this”. The _ meaning in digital text is narrower and practical: it joins words into one unbroken token, as in my_file_name or @cool_symbol_fans.

The _ symbol name in Unicode is officially LOW LINE (its older Unicode 1.0 name was SPACING UNDERSCORE). In Spanish it is called guion bajo and in German Unterstrich — both also mean “low line”. The character dates from typewriter days, when typists backspaced and struck the underscore key repeatedly to underline words by hand.

Underscore vs hyphen vs dash

These four marks are neighbours on the keyboard but sit at different heights and do different jobs:

The quick test: if the line touches the bottom of the letters, it is an underscore; if it floats in the middle, it is a hyphen or a dash. An underscore underscore pair (__) typed together is also a formatting code — in Markdown it makes text bold, while a single _word_ pair makes it italic.

How to type an underscore

Windows, Mac and Linux keyboards: hold Shift and press the hyphen key (to the right of the 0 key). That is the whole shortcut — the underscore is simply the shifted hyphen.
Windows alternative: hold Alt and type 95 on the numeric keypad, then release Alt.
Linux alternative: press Ctrl + Shift + U, type 005F, then Enter.
Phone and tablet: switch to the symbols keyboard (the “123” key, then the symbols page) and tap _. Or copy it from the grid above — one tap, no hunting through keyboard pages.

Underscore codes — Unicode, ASCII, HTML and CSS

If a form, editor or website will not accept a pasted underscore, type it by code. The ASCII code for _ is 95, which is also its decimal code everywhere else:

What underscores are used for

Usernames and email addresses: spaces are not allowed, so an underscore does the joining — cool_symbol_fans, first_name.last@example.com.
File names: the same rule keeps files safe on every system: holiday_photos_2026.zip never breaks where a space might.
Programming: the snake_case style writes variables as user_name and total_price; a lone _ is also used as a throwaway variable, and Python names like __init__ wear two each side.
Blanks and forms: a run of underscores is a fill-in line: Name: ____________. Copy the ready-made ____ from the grid above.
Emphasis in plain text: where bold and italics are unavailable, _this_ marks emphasis and __this__ marks strong emphasis — the convention Markdown still uses.

Explore more symbols

Underscore is punctuation, so its closest relatives live with the bracket symbols, the quotation mark symbol page and the dot symbol collection and the check mark symbol.

For rules and dividers, see line symbols.

Frequently asked questions

What is the underscore symbol called?

Its Unicode name is LOW LINE, and its everyday name is the underscore (also written under score). Older references call it the spacing underscore, and on typewriters it was simply the underlining key.

How do I type an underscore on a keyboard?

Hold Shift and press the hyphen key — the key to the right of 0 on most layouts. On Windows you can also hold Alt and type 95 on the numeric keypad.

What is the difference between an underscore and a hyphen?

An underscore sits on the baseline, below the letters, and joins words where spaces are banned. A hyphen floats at mid-height and joins compound words like well-known. They are different characters with different codes: _ is U+005F, the hyphen-minus is U+002D.

Why do usernames use underscores?

Usernames, email addresses and file names cannot contain spaces, and an underscore is the most readable legal separator — it keeps multi-word names like cool_symbol_fans easy to read at a glance.

What does __ mean in text?

Two underscores together are a formatting instruction in Markdown and many chat apps: __word__ renders as bold. In programming, names wrapped in double underscores (like __init__ in Python) mark special built-in behaviour.