Curly Braces in LaTeX (\left\{ x \right\})

Where it is used

Curly braces that stretch to the content height, for set-builder notation and grouped definitions.

Braces must be escaped as \{ and \} because bare braces are LaTeX grouping characters and print nothing. With \left\{ ... \right\} they grow around tall content such as \left\{ \frac{p}{q} : q \neq 0 \right\}. For a set-builder bar that also grows, use \middle| between them. For piecewise definitions, the cases environment already draws the left brace, so you do not need \left\{ ... \right. by hand. In text mode, use \textbraceleft or simply \{ inside math.

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\usepackage{amssymb}
\begin{document}
Curly Braces: $\left\{ x \right\}$

\[ \left\{ x \in \mathbb{R} \;\middle|\; x^2 < 2 \right\} \]
\end{document}

Related symbols

• Vertical Bar\left| x \right|
• Square Brackets\left[ x \right]
• Big Parentheses\Big( x \Big)
• Parentheses\left( x \right)
• Bigg Parentheses\Bigg( x \Bigg)
• Double Brackets\llbracket x \rrbracket

Frequently asked questions

How do I write Curly Braces in LaTeX?

Type \left\{ x \right\} in math mode, for example $\left\{ x \in \mathbb{R} \;\middle|\; x^2 < 2 \right\}$. It works in plain LaTeX without loading any package.

Which package do I need for \left\{ x \right\}?

None. \left\{ x \right\} is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \left\{ x \right\} in text mode, or only in math mode?

Only in math mode. Outside $...$ LaTeX stops with "Missing $ inserted", so write $\left\{ x \right\}$ in running text.