Lodash _.snakeCase() Method

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

Definition

Converts string to snake_case — words lowercased and separated by _. Part of Lodash String since 3.0.0 (stable — not deprecated).

Note: Ideal for DB columns, JSON keys, and Python-style names. Same word-splitting family as _.camelCase and _.kebabCase — only the join style differs.

Syntax

Call _.snakeCase. Start with this line.

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

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

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

Parameters

ParameterDescription
stringOptional. Input to convert; default ''

Return Value

Return ValueDescription
*New snake_case string

Lodash Examples

Example 1 — Official: Spaces

Title-style words become lowercase with underscores.

Lodash
_.snakeCase('Foo Bar');
// → 'foo_bar'
Try It Yourself

How It Works

  1. Split. Space separates Foo and Bar.
  2. Lower. Both words become lowercase.
  3. Join. Insert _ between words.
  4. Result. foo_bar.

Example 2 — Official: camelCase

Capital letters mark new words.

Lodash
_.snakeCase('fooBar');
// → 'foo_bar'
Try It Yourself

How It Works

  1. Boundary. B in Bar starts a new word.
  2. Words. foo + bar.
  3. Join. Underscore between them.
  4. Use. Map JS identifiers to DB columns.

Example 3 — Official: Punctuation

Hyphens and extra dashes are treated as separators.

Lodash
_.snakeCase('--FOO-BAR--');
// → 'foo_bar'
Try It Yourself

How It Works

  1. Strip noise. Leading/trailing - are separators.
  2. Words. FOO and BAR.
  3. Lower + join. → foo_bar.
  4. Normalize. Great for messy CSS-like labels.

Example 4 — Numbers Split Words

Digit runs often become their own word segment.

Lodash
_.snakeCase('foo2bar');
// → 'foo_2_bar'
Try It Yourself

How It Works

  1. Letters / digits. Transition at 2 splits words.
  2. Three parts. foo, 2, bar.
  3. Join. foo_2_bar.
  4. Expect. Version-like tokens may gain underscores.

Example 5 — vs kebabCase / camelCase

Same words; different join styles.

Lodash
var s = 'Foo Bar';

_.snakeCase(s);  // → 'foo_bar'
_.kebabCase(s);  // → 'foo-bar'
_.camelCase(s);  // → 'fooBar'
Try It Yourself

How It Works

  1. Same split. All three see words Foo / Bar.
  2. snake. Join with _.
  3. kebab. Join with -.
  4. camel. No separator; capitalize later words.
Compatibility

Browser & Runtime Support

_.snakeCase is a Lodash String helper since 3.0.0. It runs anywhere Lodash runs — modern browsers (CDN or bundle) and Node.js / Bun / Deno with npm install lodash.

✓ Stable · Lodash 3.0.0+

_.snakeCase()

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

100% With Lodash 3.0+
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
_.snakeCase Lodash 3.0.0+

Bottom line: Safe for production once Lodash is loaded. Prefer import snakeCase from "lodash/snakeCase" for smaller bundles. Use it to normalize labels into snake_case for APIs and databases.

Frequently Asked Questions

_.snakeCase([string='']) converts a string to snake_case: words lowercased and joined with underscores. Official: _.snakeCase('Foo Bar') → 'foo_bar'.
No. JavaScript strings are immutable. It always returns a new string.
snake_case uses underscores; kebab-case uses hyphens. Word-splitting rules are the same family of case helpers.
Spaces, hyphens, underscores, camelCase transitions, and most non-alphanumeric characters. Numbers often form their own word (foo2bar → foo_2_bar).
Empty string returns ''. Non-strings are coerced the Lodash way (null/undefined → empty string result from default '').
Use import snakeCase from "lodash/snakeCase" or require("lodash/snakeCase") for tree-shaking. Full build: import _ from "lodash" then _.snakeCase.

Next: _.split()

Split a string into an array by separator and limit.

_.split() 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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