JavaScript String Escaping Rules and Best Practices

JavaScript String Escaping

JavaScript offers three string delimiters — single quotes ('), double quotes ("), and backticks (```) — each with slightly different escaping rules. Understanding these differences is key to writing clean, bug-free code.

Single and Double Quoted Strings

Both behave identically in terms of escape sequences. The only difference is which delimiter must be escaped:

'It\'s escaped'     // escape single quote inside single-quoted string
"She said \"hi\""  // escape double quote inside double-quoted string

Supported Escape Sequences

\\'   → single quote
\\"   → double quote
\\\\   → backslash
\\n   → newline
\\r   → carriage return
\\t   → tab
\\b   → backspace
\\f   → form feed
\\0   → null character
\\uXXXX   → Unicode BMP character (4 hex digits)
\\u{XXXXX} → Unicode code point (ES6+, 1-6 hex digits)
\\xHH  → Latin-1 character (2 hex digits)

Template Literals (Backtick Strings)

Template literals handle most characters without escaping. You only need to escape backticks and the ${ sequence:

const msg = \`She said "it's fine"\`;       // no escaping needed
const code = \`Use \\\` for template literals\`; // escape backtick
const raw = \`Cost: \\${amount}\`;             // escape interpolation

JSON.stringify for Safe Escaping

When embedding data in JSON or HTML, JSON.stringify() handles all necessary escaping automatically:

const data = 'Line 1\nLine 2\t"quoted"';
console.log(JSON.stringify(data));
// Output: "Line 1\nLine 2\t\"quoted\""

Tagged Template Literals

The String.raw tag returns the raw string without processing escapes:

String.raw\`\n\t\`  // returns the four characters: \ n \ t

Common Mistakes

• Forgetting to escape backslashes in regex: new RegExp("\\\\d+") not new RegExp("\\d+").
• Using \x with only one hex digit — JavaScript requires exactly two.
• Assuming template literals need single/double quote escaping — they do not.