RegExp.prototype.flags

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The flags accessor property of RegExp instances returns the flags of this regular expression.

Try it

// Outputs RegExp flags in alphabetical order

console.log(/foo/gi.flags);
// Expected output: "gi"

console.log(/^bar/muy.flags);
// Expected output: "muy"

RegExp.prototype.flags has a string as its value. Flags in the flags property are sorted alphabetically (from left to right, e.g., "dgimsuvy"). It actually invokes the other flag accessors (hasIndices, global, etc.) one-by-one and concatenates the results.

All built-in functions read the flags property instead of reading individual flag accessors.

The set accessor of flags is undefined. You cannot change this property directly.

Examples

Using flags

js
/foo/ig.flags; // "gi"
/^bar/myu.flags; // "muy"

Specifications

Specification

ECMAScript® 2027 Language Specification
# sec-get-regexp.prototype.flags

Browser compatibility

Enable JavaScript to view this browser compatibility table.

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This page was last modified on Jul 10, 2025 by MDN contributors.

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Standard built-in objects
RegExp
Constructor
1. RegExp()
Static methods
1. escape()
Static properties
Instance methods
Instance properties
Inheritance
Object/Function
Static methods
Static properties
Instance methods
Instance properties
1. __proto__
2. constructor