JavaScript RegExp $ End Anchor

Beginner
5 min read
Updated: Oct 2026
3 examples
Live preview
JavaScript RegExp $ end anchor — match at the end of a string or line
Definition

What Is $?

$ is a zero-width end anchor. It matches a position—not a character—at the end of the input. With the m flag, it also matches at the end of each line. Use it to require a suffix.

Remember
/pattern$/          // must finish at end of string
/pattern$/m         // end of each line too

/world$/.test("hello world")  → true
/world$/.test("world peace")  → false

$ consumes nothing (zero-width)
pair with ^ for full-string match: /^…$/
UsePrefer
Ends with a word/world$/
End of each line/end$/m or /end$/gm
File extension/\.png$/i
Approach

How to Use $

Put $ at the end of the pattern (or before a trailing flag).

  1. Write the text or group that must appear last, then add $ — e.g. /ing$/.
  2. Call test, match, or replace as usual.
  3. Add m when you need the end of every line in multi-line text.
  4. Do not confuse pattern $ with $1 in a replace replacement string.
PieceRequired?Role
$YesAssert end of string (or line with m)
Suffix patternUsualWhat must appear just before the end
m flagOptionalTreat each line end as a match position

Pseudocode

Pseudocode
re = /suffix$/

find "suffix" in text
if found and position after it is end-of-input
   (or end-of-line when m is on):
    match ✓
else:
    fail

// $ itself matches no characters
Reference

Cheat Sheet

Keep these end-anchor facts handy.

TopicDetail
Syntax/pattern$/
DefaultEnd of the whole string
With mAlso before each newline
Zero-widthDoes not consume characters
vs ^^ = start; $ = end
vs \b\b = word edge; $ = string/line end
In replace$1 = group; pattern $ is different
StandardES3+ (universal)
Try it

Live Preview

Test end-anchor patterns against sample strings.

Browser demo of the $ end anchor — same idea as the examples below.

Result
/world$/.test("hello world")
→ true

/* "world" sits at the end of the string */
Code

JavaScript Examples

Short, copy-ready snippets. Open DevTools Console, or use Try It Yourself for a live editor.

Example 1 — Require a Suffix with $

Match only when the word sits at the end of the string.

JavaScript
console.log(/world$/.test("hello world"));  // true
console.log(/world$/.test("say world"));    // true
console.log(/world$/.test("world peace"));  // false
Try It Yourself

How It Works

  1. Find the text. The engine looks for "world".
  2. Check the end. After that match, $ requires no more characters.
  3. Success cases. "hello world" and "say world" end with world.
  4. Failure case. In "world peace", characters continue after world → false.

Example 2 — End of Each Line with $ and m

Match a suffix on every line, not only the last line of the string.

JavaScript
const text = "line one end\nline two end\nno match";

console.log(/end$/.test(text));     // false
console.log(/end$/m.test(text));    // true
console.log(text.match(/end$/gm));  // ["end", "end"]
Try It Yourself

How It Works

  1. Without m. $ looks at the whole string end — "no match" → false.
  2. With m. $ also matches before each newline.
  3. Lines 1 and 2 win. Both end with "end".
  4. gm collects them. You get two matches from the first two lines.

Example 3 — Validate a File Extension

Require the name to end with .jpg, .jpeg, or .png.

JavaScript
const isImage = /\.(jpe?g|png)$/i;

console.log(isImage.test("photo.jpg"));      // true
console.log(isImage.test("photo.JPEG"));     // true
console.log(isImage.test("photo.jpg.bak"));  // false
Try It Yourself

How It Works

  1. Escape the dot. \. means a literal period, not “any character.”
  2. Allow variants. jpe?g matches jpg or jpeg; |png adds PNG.
  3. Anchor the end. $ rejects names like photo.jpg.bak.
  4. Ignore case. The i flag accepts .JPEG as well.

Edge Cases & Pitfalls

Check these before relying on $.

replace

Pattern $ ≠ replacement $1

In a pattern, $ is an end anchor. In a replacement string, $1 means capture group 1 and $$ is a literal dollar.

newline

Trailing \n can still match

In JavaScript, $ may match before a final trailing newline even without m. Test with your real strings.

word

$ is not a word-boundary

For “ends a word but not necessarily the string,” use \b instead of $.

escape

Literal dollar needs escaping

To match a $ character in text, use /\$/. Unescaped $ is always the end anchor.

Compatibility

Browser & Runtime Support

The $ end anchor is part of core JavaScript regular expression syntax (ES3+).

✓ Baseline · ES3+

RegExp $ end anchor

Supported in every browser and Node.js version. Multiline $ with the m flag is equally universal.

99% Universal syntax
Google Chrome Supported · Desktop & Mobile
Full support
Mozilla Firefox Supported · Desktop & Mobile
Full support
Apple Safari Supported · macOS & iOS
Full support
Microsoft Edge Supported · Chromium
Full support
Internet Explorer No native support · Use a polyfill
Polyfill
Opera Supported · Modern versions
Full support
Samsung Internet Supported · Android
Full support
Bun Supported · JavaScript runtime
Supported
Deno Supported · JavaScript runtime
Supported
Node.js Supported · Server runtime
Supported
Android WebView Supported · Modern WebView
Full support
$ Excellent

Bottom line: Safe everywhere. Use $ when a pattern must finish at the end of a string or line.

Analysis

Performance Notes

ApproachCostBest for
/suffix$/O(n)Suffix / extension checks
str.endsWith("x")O(k)Fixed literal suffixes (no regex needed)
/end$/gmO(n)Every line end in multi-line text

Anchors are cheap assertions. Prefer endsWith for a fixed literal; use $ when you need a pattern (extensions, optional parts, or case flags).

Remember

Key Takeaways

  • Role: $ asserts the end of the string (or line with m).
  • Zero-width: it matches a position, not a character.
  • Pair: use ^ + $ for a full-string match.
  • Context: pattern $ ≠ replacement $1.

One line: put $ at the end of a pattern when the match must finish at the end of the string or line.

Frequently Asked Questions

In a pattern, $ is a zero-width end anchor. It matches a position at the end of the input string, or—when the m (multiline) flag is set—immediately before each newline. It does not consume any characters.
No. In a pattern, $ asserts end of string or line. In a replacement string, $1 / $2 refer to capture groups and $$ is a literal dollar. The meaning depends on context.
Use $ with m when your text has newlines and you want the end of each line—not only the very last character of the whole string. Example: /end$/m matches end at the close of every line.
$ matches end of string or line (with m). \b matches a word boundary. /ing\b/ finds a word ending in ing; /ing$/ requires ing at the string or line end.
In JavaScript, $ can also match before a final trailing newline even without m. Prefer testing with your real input, and use m when you need every internal line end.
The $ anchor is core JavaScript regex syntax since ES3. It works in every browser and Node.js version.

Next: ?! negative lookahead

Learn how to assert that a pattern is not followed by something else.

?! tutorial →

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

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