Lodash _.lowerCase() Method

Beginner
5 min read
Updated: Nov 2026
5 examples
String
Decorative image with the word LOWERCASE

Definition

Converts string, as space-separated lowercase words. Separators and punctuation are stripped; camelCase splits into words. Part of Lodash String (since 3.0.0 — not deprecated).

Pass the string and options shown below. Check the return type before you chain another helper.

Syntax

Call _.lowerCase. Start with this line.

Lodash
_.lowerCase([string=''])
CallWhat it does
_.lowerCase([string=''])Primary signature.
_.lowerCase(string)Transform or inspect a string.

Prefer import lowercase from "lodash/lowercase" when you want a smaller bundle.

Library declarations
Lodash
_.lowerCase([string=''])

Parameters

ParameterDescription
stringOptional. Value to convert (default ''; non-strings are coerced)

Return Value

Return ValueDescription
*New space-separated lowercase string

Lodash Examples

Example 1 — Official: Hyphenated String

Separators drop; words become a lowercase phrase.

Lodash
console.log(_.lowerCase("--Foo-Bar--"));
// 'foo bar'
Try It Yourself

How It Works

  1. Split. Hyphens mark word boundaries.
  2. Clean. Leading/trailing separators are removed.
  3. Lower. Each word becomes lowercase.
  4. Docs. Matches the official first example.

Example 2 — Official: camelCase Splits

Capitals start new words — unlike _.toLower.

Lodash
console.log(_.lowerCase("fooBar"));
// 'foo bar'
Try It Yourself

How It Works

  1. Boundary. B starts a new word.
  2. Words. You get foo and bar.
  3. Join. A space connects them.
  4. Contrast. _.toLower("fooBar") → foobar.

Example 3 — Official: Underscored Caps

Underscores become spaces; letters drop to lowercase.

Lodash
console.log(_.lowerCase("__FOO_BAR__"));
// 'foo bar'
Try It Yourself

How It Works

  1. Split. Underscores mark word edges.
  2. Trim. Edge underscores disappear.
  3. Lower. FOO / BAR become lowercase.
  4. Docs. Matches the official third example.

Example 4 — lowerCase vs toLower

Same input, different jobs.

Lodash
var s = "--Foo-Bar--";

console.log(_.lowerCase(s)); // 'foo bar'
console.log(_.toLower(s));   // '--foo-bar--'
Try It Yourself

How It Works

  1. lowerCase. Words + spaces; separators gone.
  2. toLower. Letters only; separators stay.
  3. Pick. Phrase vs keep-format lowercase.
  4. Next. See the _.toLower tutorial.

Example 5 — Pair with _.upperCase

Same word split, opposite letter case.

Lodash
var s = "--Foo-Bar--";

console.log(_.lowerCase(s)); // 'foo bar'
console.log(_.upperCase(s)); // 'FOO BAR'
Try It Yourself

How It Works

  1. Shared. Both split on the same word rules.
  2. lowerCase. Joins as lowercase words.
  3. upperCase. Joins as uppercase words.
  4. Next. See the _.upperCase tutorial.
Compatibility

Browser & Runtime Support

_.lowerCase is a Lodash String helper available since 3.0.0. It runs anywhere Lodash runs — modern browsers (via CDN or bundle) and Node.js / Bun / Deno with npm install lodash. There is no single native equivalent: you would combine word splitting with toLowerCase.

✓ Stable · Lodash 4.x

_.lowerCase()

Available in [email protected] full builds and the lodash/lowerCase modular import. Works in evergreen browsers and current Node LTS when Lodash is installed.

100% With Lodash 4.x
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
_.lowerCase Since 3.0.0

Bottom line: Safe for production once Lodash is on the page. Prefer import lowerCase from "lodash/lowerCase" for smaller builds. Use when you need a human-readable lowercase phrase, not just letter case.

Frequently Asked Questions

_.lowerCase([string='']) converts a string to space-separated lowercase words using Lodash word-boundary rules. Official: _.lowerCase('--Foo-Bar--') → 'foo bar'.
_.toLower only changes letter case and keeps separators (--Foo-Bar-- → --foo-bar--). _.lowerCase splits into words and joins with spaces (→ foo bar).
toLowerCase only lowercases. lowerCase also removes punctuation/separators and inserts spaces between words.
No. Strings are immutable. _.lowerCase always returns a new string.
Use _.kebabCase for URL-style foo-bar, _.snakeCase for foo_bar. Use _.lowerCase when you want a readable lowercase phrase with spaces.
Use import lowerCase from "lodash/lowerCase" or require("lodash/lowerCase"). Full build: import _ from "lodash" then _.lowerCase.

Next: _.lowerFirst()

Lowercase only the first character of a string.

_.lowerFirst() 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.

AWS Certified Developer – Associate (Credly)

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Lodash _.kebabCase() Method — Hyphenated Lowercase Words Lodash _.lowerFirst() Method — Lowercase First Character