JavaScript RegExp \v Metacharacter

What You’ll Learn

The \v metacharacter matches a vertical tab (VT, U+000B)—a legacy control character that advances to the next vertical tab stop. It is rarely seen in modern text, but knowing it helps when cleaning old files or understanding the full \s whitespace class.

Introduction

JavaScript regular expressions include escapes for several control characters. You already know \t (horizontal tab) and \n (newline). The \v metacharacter targets the vertical tab—a separate character with its own Unicode code point.

Vertical tabs are uncommon in web content, JSON, and everyday strings. They appear more often in legacy printer formats, old terminal data, or accidentally corrupted text. When you need to detect or strip them, /\v/ gives you precise control instead of matching every whitespace type with \s.

Understanding the \v Metacharacter

\v matches the vertical tab character (Unicode U+000B, ASCII 11). In JavaScript string literals, "\v" creates the same character that /\v/ matches in a regex.

const text = "line1\vline2";

/\v/.test(text);           // true
/\v/.test("hello world");  // false

"\v" === "\u000B";         // true (same code point)

Vertical tab is included in \s but is not the same as horizontal tab (\t) or newline (\n). Each escape matches exactly one specific control character.

How to Use \v in JavaScript

Use \v in detection, cleaning, splitting, and validation workflows:

/\v/.test("a\vb");                 // true
"one\vtwo".split(/\v/);           // ["one", "two"]
"hello\vworld".replace(/\v/g, ""); // "helloworld"
/\s/.test("x\vy");                 // true (\v is whitespace)

Pair \v with the global flag for bulk removal, or combine with other control-character escapes when sanitizing imported legacy data.

📝 Syntax

\v              // one vertical tab
\v+             // one or more vertical tabs
/\v/g           // global: every vertical tab
split(/\v/)      // split on vertical tab
\s              // any whitespace (includes \v)

Common patterns

• /\v/ — detect whether a vertical tab exists.
• /\v/g with replace("", ...) — remove all vertical tabs.
• /[\t\n\v\r\f]/ — match common control whitespace explicitly.
• /\u000B/ — same character using the Unicode escape form.

Examples Gallery

Open DevTools Console (F12) or use Try-it links. Examples cover detection, comparison with other control chars, removal, the \s class, and splitting on a vertical tab delimiter.

console.log(/\v/.test("hello"));       // false
console.log(/\v/.test("a\vb"));        // true
console.log(/\v/.test("hello world")); // false (space only)

false
true
false

const sample = "a\vb\tc\nd";

console.log(sample.match(/\v/g).length); // 1
console.log(sample.match(/\t/g).length); // 1
console.log(sample.match(/\n/g).length); // 1

1
1
1

const dirty = "hello\vworld\v!";

const clean = dirty.replace(/\v/g, "");
console.log(clean);              // "helloworld!"
console.log(dirty.length);       // 13 (includes 2 VT chars)
console.log(clean.length);       // 11

helloworld!
13
11

const text = "x\vy";

console.log(/\s/.test(text));  // true
console.log(text.split(/\s/)); // ["x", "y"]
console.log(/\v/.test(text));  // true

true
["x", "y"]
true

const row = "one\vtwo\vthree";

const parts = row.split(/\v/);
console.log(parts);        // ["one", "two", "three"]
console.log(parts.join(" + ")); // "one + two + three"

["one", "two", "three"]
one + two + three

🚀 Common Use Cases

• Legacy file cleanup — strip vertical tabs from old terminal or printer exports.
• Data sanitization — remove invisible control characters before validation.
• Whitespace auditing — detect which control chars appear in pasted content.
• Logging — flag unexpected VT characters in log pipelines.
• Understanding \s — know every character the whitespace class can match.
• Normalization — convert vertical tabs to spaces or newlines for display.

Important Considerations

• Very rare — most modern text never contains \v; do not assume it is present.
• Not horizontal tab — \v is vertical tab; use \t for column separators.
• Part of \s — /\s+/ also matches vertical tabs, but mixes all whitespace types.
• Global flag — omitting g in replace() removes only the first vertical tab.
• Same as \u000B — /\v/ and /\u000B/ match the identical character.

📝 Notes

• \v is vertical tab (U+000B, ASCII 11).
• Vertical tab is included in the \s whitespace class.
• Review \t for horizontal tab and \n for newlines.
• Previous metacharacter: \uXXXX Unicode escape.
• Next metacharacter: \w word character.
• Equivalent Unicode form: \u000B matches the same character as \v.

💡 Best Practices