Backslash \

An easy way to remember: the top of a backslash leans back, to the left.

• Forward slash (/): web addresses (https://example.com/page), dates (11/13/2026), fractions (1/2) and “and/or.”
• Backslash: Windows file paths (C:\Users\Jane\Documents) and programming.

Never use a backslash in a web address. Browsers often fix it quietly, but links typed with backslashes can break in emails, apps and code. In everyday writing there is almost no use for a backslash at all; and\or is always a typo for and/or.

• Escape sequences: in most languages, \n is a new line, \t a tab and \" a quote inside a string. To get one backslash, type two: \\.
• Regular expressions: \d matches a digit and \. matches a literal period.
• LaTeX: every command starts with a backslash, such as \frac or \alpha. To print the character itself, use \textbackslash.
• Markdown: a backslash before a symbol such as * or _ makes it literal. That is why the shrug kaomoji loses an arm in chat apps unless you add extra backslashes.
• Windows paths in code: write C:\\Temp inside a C# or Python string, or use forward slashes, which Windows file functions also accept.

• ∖ (set minus) is the math operator for set difference, as in A ∖ B. In LaTeX it is \setminus.
• ⧵ (reverse solidus operator) is another math character that looks the same.

On Japanese systems that use the older Shift_JIS encoding and fonts, the backslash code displays as a yen sign, so Windows paths look like C:¥Users¥Jane. It is still the same character underneath. Korean systems have a similar quirk with the won sign ₩.

If pressing Shift with the backslash key gives you a vertical bar (|), that is expected: the pipe is the shifted character on the same key.