A modern Lodash alternative

modern-fns covers the Lodash methods most applications actually use, with native ES modules, types generated from the source, and immutability as a rule rather than a per-method detail.

npm install modern-fns

// Lodash
import _ from 'lodash';
_.groupBy(users, 'role');

// modern-fns
import { groupBy } from 'modern-fns';
groupBy(users, 'role');

Why people migrate

• Bundle size. import _ from 'lodash' pulls the whole library. modern-fns is one function per file with sideEffects: false, so import { chunk } costs 0.20 kB gzipped.
• No @types package. Lodash ships no types of its own; you install and version @types/lodash alongside it. modern-fns generates declarations from its own source.
• Native ESM. Lodash's main package has no exports field and no module entry — the ESM build is the separate lodash-es package. modern-fns ships both from one package.
• Predictable mutation. In Lodash, _.set, _.merge, _.pull and _.remove mutate their argument while _.map and _.sortBy do not. In modern-fns nothing mutates.

Migration mapping

Arrays

Lodash	modern-fns
_.chunk	chunk
_.uniq	unique
_.uniqBy	uniqueBy
_.groupBy	groupBy
_.keyBy	indexBy
_.partition	partition
_.sortBy	sortBy
_.orderBy	orderBy
_.flatten / _.flattenDeep	flatten / flattenDeep
_.compact	compact
_.difference / _.intersection / _.union	difference / intersection / union
_.zip / _.unzip	zip / unzip
_.head / _.last	first / last
_.take / _.takeRight / _.drop / _.dropRight	same names
_.range	range

Objects

Lodash	modern-fns	Note
_.get	get
_.set	set	Lodash mutates; modern-fns returns a new object.
_.has / _.unset	has / unset	unset is immutable here
_.pick / _.omit	pick / omit
_.cloneDeep	deepClone
_.merge	deepMerge	Lodash mutates its first argument; deepMerge returns a new object.
_.mapValues / _.mapKeys	mapValues / mapKeys
_.isEqual	isEqual
_.isEmpty	isEmpty

Strings, numbers and types

Lodash	modern-fns
_.capitalize / _.upperFirst	capitalize
_.camelCase / _.kebabCase / _.snakeCase	same names
_.startCase	capitalizeWords
_.truncate	truncate
_.escape / _.unescape	escapeHtml / unescapeHtml
_.clamp, _.round, _.floor, _.ceil, _.random	same names in number
_.toNumber	toNumber — also parses "₹1,299.50"
_.isNil, _.isString, _.isNumber, _.isBoolean, _.isArray, _.isFunction	same names in value
_.isPlainObject	isObject
_.defaultTo	defaultTo

Functions and collections

Lodash	modern-fns
_.debounce / _.throttle	debounce / throttle
_.memoize / _.once	memoize / once
_.identity / _.noop	identity / noop
_.flow / _.flowRight	pipe / compose
_.forEach, _.map, _.filter, _.find, _.some, _.every, _.size	collection module — same names, each instead of forEach

Behavioural differences to watch for

set and deepMerge do not mutate. This is the one migration change that bites silently:

// Lodash — mutates in place, return value often ignored
_.set(state, 'user.city', 'Kochi');

// modern-fns — you must use the return value
state = set(state, 'user.city', 'Kochi');

isEmpty(0) is false. Lodash returns true for numbers because they have no length. modern-fns treats 0 and false as values, not absences.

debounce has no maxWait. It supports leading, trailing, cancel(), flush() and pending(). If you rely on maxWait, keep Lodash for that call site.

Selectors are keyof T or a function. Lodash's _.matches / _.property shorthands (_.filter(users, { active: true })) are not supported — write the predicate out.

What modern-fns does not have

No equivalent exists for _.template, _.curry, _.partial, the lodash/fp module, _.countBy, _.sumBy, _.maxBy, _.minBy, _.times, _.sample, _.shuffle, _.deburr, _.zipObject, _.fromPairs or _.toPairs.

Several of those are one-liners in modern JavaScript — Object.fromEntries, Object.entries, Array.from({ length: n }), Math.max(...values.map(fn)) — which is exactly why they were left out. See the design philosophy.

The two libraries coexist happily in one project, so a partial migration is a perfectly reasonable outcome. Read the detailed comparison before deciding.