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decamelcase-keys v1.1.1

Convert object keys to snake case

decamelcase-keys · Build Status npm version minzipped size

Convert object keys from camelCase/PascalCase to snake_case or into a lowercased one with a custom separator.

Distinctive features from similar packages:

  • convertible object keys are cached to increase performance when re-converting a key
  • supports different languages ​​for writing convertible keys (not only English)

This project uses decamelize and was made on the basis of camelcase-keys


npm i decamelcase-keys


const decamelcaseKeys = require('decamelcase-keys');

// Convert an object
decamelcaseKeys({fooBar: true});
//=> {foo_bar: true}

// Convert an array of objects
decamelcaseKeys([{fooBar: true}, {barFoo: false}]);
//=> [{foo_bar: true}, {bar_foo: false}]

// Recurse nested objects
decamelcaseKeys({fooBar: true, nested: {unicornRainbow: true}}, {deep: true});
//=> {foo_bar: true, nested: {unicorn_rainbow: true}}

// Convert object keys with a custom separator (for example, in kebab case)
decamelcaseKeys({FooBar: true, Nested: {UnicornRainbow: true}}, {deep: true, separator: '-'});
//=> {'foo-bar': true, nested: {'unicorn-rainbow': true}}

// Exclude keys from being snake-cased
decamelcaseKeys({fooBar: true, barFoo: false}, {exclude: ['barFoo']});
//=> {foo_bar: true, barFoo: false}

// Exclude children at the given object paths
decamelcaseKeys({aB: 1, aC: {cD: 1, cE: {eF: 1}}}, {deep: true, stopPaths: ['aC.cE']});
//=> {a_b: 1, a_c: {c_d: 1, c_e: {eF: 1}}}


decamelcaseKeys(input, options?)


Type: object | object[]

An object or array of objects to snake-case.


Type: object


Type: boolean
Default: false

Recurse nested objects and objects in arrays.


Type: string
Default: '_'

The separator to use to put in between the words.


Type: Array<string | RegExp>
Default: []

Exclude keys from being snake-cased.


Type: string[]
Default: []

Exclude children at the given object paths in dot-notation from being snake-cased. For example, with an object like {a: {b: '🦄'}}, the object path to reach the unicorn is 'a.b'.

    aB: 1,
    aC: {
        cD: 1,
        cE: {
            eF: 1
}, {
    deep: true,
    stopPaths: [
    a_b: 1,
    a_c: {
        c_d: 1,
        c_e: {
            eF: 1


See camelcase-keys for the inverse.


decamelcase-keys is MIT licensed.

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