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Choosing a plural form

Internationalization & Formatting

Intl.PluralRules

Baseline widely availablederived from web-features, captured 2026-09-20
  • Chrome63
  • Edge18
  • Firefox58
  • Safari13

Features it needs

Picking between "1 file" and "2 files" by testing count === 1 is only correct in English, and barely. Russian needs one form for 3 and another for 5, and Polish and Arabic have more. Intl.PluralRules answers which category a number falls into for a locale, so the branching stops being a guess. It returns the category rather than the word, which is the part worth knowing before reaching for it.

When this applies

Choosing between singular and plural wording for a count.

The native approach

Intl.PluralRules
const pr = new Intl.PluralRules("en-US");
const forms = { one: "file", other: "files" };
`${count} ${forms[pr.select(count)]}`; // "1 file", "2 files"

// Ordinals are the same API with a different type.
new Intl.PluralRules("en-US", { type: "ordinal" }).select(22); // "two"
Live example

MDN reference

When the dependency is still right

An answer that always says "the platform covers it" is worse than no answer. These are the cases where this one does not hold.

  • You need the plural word itself. Intl.PluralRules returns a category such as "one" or "other" and never inflects anything, so "person" to "people" and "index" to "indices" still need pluralize or a table of your own. This is the difference that decides most cases.
  • You pluralise arbitrary nouns you do not control, such as user-supplied or database-driven labels. A category is only useful when you already hold both forms, which you cannot if the noun is unknown at build time.
  • You singularise as well as pluralise. pluralize goes both directions and this API goes neither.
  • Your strings already run through an ICU message catalogue. It has plural selection built in and doing it twice is how the two disagree.

Signs it was hand-rolled

No package is involved in any of these, so nothing would match in a package.json. If the code looks like one of them, this rule applies anyway, and the conditions above still decide.

  • a count === 1 ternary picking between two words, or a bare + "s" appended to a noun
  • a lookup of irregular plurals kept next to the component that renders them

Packages this covers

Minified and gzipped, captured 2026-09-20.