Special characters

LaTeX has ten characters you cannot just type and expect to see: # $ % & _ { } ~ ^ \. Each one is reserved for a special job — starting a comment, switching to math, beginning a command, and so on. This page covers what each does, and how to print the character itself when you actually want it.

The ten reserved characters

A reserved character is one that LaTeX uses as part of its syntax, so typing it in your text triggers a behavior instead of printing. Type % and the rest of that line vanishes as a comment; type $ and you switch into math mode. To get such a character to appear as itself on the page, you have to do a little extra.

Here is what each one does. # stands for an argument in a macro definition; $ begins and ends math mode; % starts a comment (the rest of the line is ignored); & separates the columns (cells) of a table or alignment. _ and ^ introduce a subscript and a superscript in math; { and } delimit an argument or a group. ~ produces a non-breaking interword space, and \ (backslash) begins every command.

Printing the character itself

Seven of the ten are easy: just put a single backslash in front. That gives \#, \$, \%, \&, \_, \{, \}. Typing \$1.23, for example, prints $1.23. The backslash signals “the next character is itself, not the start of a command.”

The remaining three are trickier. Print ~ with \textasciitilde (or \~{}), and ^ with \textasciicircum (or \^{}). Written alone, \~ and \^ are *accent* commands and would place a tilde or hat over the next letter; adding an empty {} gives the accent nothing to sit on, leaving the bare symbol.

Finally, the backslash itself: print it with \textbackslash. **Do not use \\** — that is not two backslashes but the line-break (new-line) command. This is an easy and common trap.

The commands \textbackslash, \textasciitilde, and \textasciicircum are part of the current LaTeX kernel and need no extra package (historically they came from textcomp). Note that some text fonts lack a standalone tilde or caret glyph in the body face; in those fonts these text-symbol commands are the reliable way to get the mark.

A worked example

Let us print a sentence packed with reserved characters, such as 100% & $5 cost #1. Each of %, &, $, # is escaped with a leading backslash.

100\% \& \$5 cost \#1

% backslash, tilde and caret need their own commands:
A path: C:\textbackslash Users \\
Math symbols out of math: \textasciitilde{} and \textasciicircum{}

The first line sets as 100% & $5 cost #1. Below it, a Windows-style path uses a backslash (\textbackslash), and a standalone tilde and caret use \textasciitilde{} and \textasciicircum{} (the \\ at the end of the line is the command that breaks the output line — it does not print a backslash).

When you have many specials, or a URL

Escaping a dense snippet of code or symbols one character at a time is tedious. For that, the verbatim mechanism helps. Inline, write \verb|...|, fencing the text with any character that does not appear inside it (here |); its contents are set as-is in a typewriter font, with all special meanings switched off. For several lines, use the verbatim environment.

Use \verb|a_b^c & d%| to show specials literally.

\begin{verbatim}
foo_bar = 100% & #1   % all printed as-is
\end{verbatim}

For strings that tend to contain ~, #, %, or _ — URLs above all — reach for \url{...} from the url (or hyperref) package. It handles the reserved characters inside automatically, sets them in a monospaced font, and breaks the line sensibly, so no manual escaping is needed.

\usepackage{hyperref}
% ...
See \url{https://example.com/path?id=1#sec_2~ok}

In short: escape one-off symbols as in the table, hand dense snippets to \verb/verbatim, and let \url{} take URLs. The wider logic of the syntax is covered in “Syntax rules,” and the many text symbols you can use in the body live on the “Text symbols” page.