Intl.NumberFormat.prototype.resolvedOptions()

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2017.

The resolvedOptions() method of Intl.NumberFormat instances returns a new object with properties reflecting the options computed during initialization of this NumberFormat object.

Try it

const numberFormat1 = new Intl.NumberFormat("de-DE"); const options1 = numberFormat1.resolvedOptions(); console.log(options1.locale); // Expected output (Firefox / Safari): "de-DE" // Expected output (Chrome): "de" console.log(options1.numberingSystem); // Expected output: "latn" console.log(options1.style); // Expected output: "decimal"

Syntax

resolvedOptions()

Parameters

None.

Return value

A new object with properties reflecting the options computed during the initialization of this NumberFormat object. The object has the following properties, in the order they are listed:

locale: The BCP 47 language tag for the locale actually used, determined by the locale negotiation process. Only the nu Unicode extension key, if requested, may be included in the output.
numberingSystem: The value provided for this property in the options argument, or using the Unicode extension key "nu", with default filled in as needed. It is a supported numbering system for this locale. The default is locale dependent.
style: The value provided for this property in the options argument, with default filled in as needed. It is either "decimal", "percent", "currency", or "unit". The default is "decimal".
currencyOptional: The value provided for this property in the options argument. It is only present if style is "currency". It is an ISO 4217 currency code; see Intl.supportedValuesOf(). It is required if style is "currency" so there is no default.
currencyDisplayOptional: The value provided for this property in the options argument, with default filled in as needed. It is only present if style is "currency". It is either "code", "symbol", "narrowSymbol", or "name". The default is "symbol".
currencySignOptional: The value provided for this property in the options argument, with default filled in as needed. It is only present if style is "currency". It is either "standard" or "accounting". The default is "standard".
unitOptional: The value provided for this property in the options argument. It is only present if style is "unit". It is a sanctioned unit identifier from the full CLDR list. It is required if style is "unit" so there is no default.
unitDisplayOptional: The value provided for this property in the options argument, with default filled in as needed. It is only present if style is "unit". It is either "short", "narrow", or "long". The default is "short".
minimumIntegerDigits: The value provided for this property in the options argument, with default filled in as needed. It is an integer between 1 and 21. The default is 1.
minimumFractionDigits, maximumFractionDigitsOptional: The value provided for these properties in the options argument, with defaults filled in as needed. They are only present if necessary; see digit options. It is an integer between 0 and 100.
minimumSignificantDigits, maximumSignificantDigitsOptional: The value provided for these properties in the options argument, with defaults filled in as needed. They are only present if necessary; see digit options. It is an integer between 1 and 21.
useGrouping: The value provided for this property in the options argument, with default filled in as needed, and with some values normalized. It is either "always", "auto", "min2", or the boolean false. The default is "min2" if notation is "compact", and "auto" otherwise.
notation: The value provided for this property in the options argument, with default filled in as needed. It is either "standard", "scientific", "engineering", or "compact". The default is "standard".
compactDisplayOptional: The value provided for this property in the options argument, with default filled in as needed. It is only present if notation is "compact". It is either "short" or "long". The default is "short".
signDisplay: The value provided for this property in the options argument, with default filled in as needed. It is either "auto", "always", "exceptZero", "negative", or "never". The default is "auto".
roundingIncrement: The value provided for this property in the options argument, with default filled in as needed. It is one of 1, 2, 5, 10, 20, 25, 50, 100, 200, 250, 500, 1000, 2000, 2500, and 5000. The default is 1.
roundingMode: The value provided for this property in the options argument, with default filled in as needed. It is one of "ceil", "floor", "expand", "trunc", "halfCeil", "halfFloor", "halfExpand", "halfTrunc", and "halfEven". The default is "halfExpand".
roundingPriority: The value provided for this property in the options argument, with default filled in as needed. It is either "auto", "morePrecision", or "lessPrecision". The default is "auto".
trailingZeroDisplay: The value provided for this property in the options argument, with default filled in as needed. It is either "auto" or "stripIfInteger". The default is "auto".

Examples

Using the `resolvedOptions` method

// Create a NumberFormat const de = new Intl.NumberFormat("de-DE", { style: "currency", currency: "USD", maximumFractionDigits: 2, roundingIncrement: 5, roundingMode: "halfCeil", }); // Resolve the options const usedOptions = de.resolvedOptions(); console.log(usedOptions.locale); // "de-DE" console.log(usedOptions.numberingSystem); // "latn" console.log(usedOptions.compactDisplay); // undefined ("notation" not set to "compact") console.log(usedOptions.currency); // "USD" console.log(usedOptions.currencyDisplay); // "symbol" console.log(usedOptions.currencySign); // "standard" console.log(usedOptions.minimumIntegerDigits); // 1 console.log(usedOptions.minimumFractionDigits); // 2 console.log(usedOptions.maximumFractionDigits); // 2 console.log(usedOptions.minimumSignificantDigits); // undefined (maximumFractionDigits is set) console.log(usedOptions.maximumSignificantDigits); // undefined (maximumFractionDigits is set) console.log(usedOptions.notation); // "standard" console.log(usedOptions.roundingIncrement); // 5 console.log(usedOptions.roundingMode); // halfCeil console.log(usedOptions.roundingPriority); // auto console.log(usedOptions.signDisplay); // "auto" console.log(usedOptions.style); // "currency" console.log(usedOptions.trailingZeroDisplay); // auto console.log(usedOptions.useGrouping); // auto

Specifications

Specification
ECMAScript® 2026 Internationalization API Specification # sec-intl.numberformat.prototype.resolvedoptions