1o1-utils vs es-toolkit

es-toolkit is a modern, high-performance utility library from the Toss team. It’s a direct lodash alternative with broader coverage than 1o1-utils but a larger footprint.

At a glance

	1o1-utils	es-toolkit
Bundle size (gzip)	~2 kB total	~6 kB
Dependencies	0	0
TypeScript	Native, strict	Native
Tree-shaking	Full	Full
Named parameters	Yes	No (lodash-style positional)
Scope	18 focused utilities	200+ utilities
Maintained by	Pedro Troccoli	Toss (fintech)

API equivalence

es-toolkit	1o1-utils	Notes
`chunk(arr, n)`	`chunk({ array, size })`	Named params
`keyBy(arr, fn)`	`arrayToHash({ array, key })`	Key-based only
`groupBy(arr, fn)`	`groupBy({ array, key })`
`sortBy(arr, keys)`	`sortBy({ array, key })`
`uniq` / `uniqBy`	`unique({ array, key? })`	Unified
`cloneDeep(obj)`	`cloneDeep({ obj })`
`merge(a, b)`	`deepMerge({ target, source })`	Explicit “deep”
`isEmpty(v)`	`isEmpty({ value })`
`omit(obj, keys)`	`omit({ obj, keys })`
`pick(obj, keys)`	`pick({ obj, keys })`
`capitalize(str)`	`capitalize({ str })`
`camelCase` / `snakeCase` / `kebabCase`	`transformCase({ str, to })`	One function
`debounce(fn, ms)`	`debounce({ fn, wait })`
`throttle(fn, ms)`	`throttle({ fn, wait })`

Side by side

// es-toolkit — lodash-style, positional
import { chunk, keyBy, pick, debounce } from "es-toolkit";

const pages = chunk(items, 10);
const byId = keyBy(users, (u) => u.id);
const picked = pick(user, ["id", "name"]);
const search = debounce(fn, 300);

// 1o1-utils — named params, declarative
import { chunk } from "1o1-utils/chunk";
import { arrayToHash } from "1o1-utils/array-to-hash";
import { pick } from "1o1-utils/pick";
import { debounce } from "1o1-utils/debounce";

const pages = chunk({ array: items, size: 10 });
const byId = arrayToHash({ array: users, key: "id" });
const picked = pick({ obj: user, keys: ["id", "name"] });
const search = debounce({ fn, wait: 300 });

When should you choose es-toolkit?

You want a near drop-in lodash replacement with familiar positional API
You need broader coverage (math, chain, curry, partial, memoize, FP suite)
You’re migrating existing lodash code and want minimal refactor
You value a library backed by a large fintech team (Toss)

When should you choose 1o1-utils?

3× smaller bundle (2 kB vs 6 kB)
Named parameters — self-documenting call sites, no signature guessing
Benchmarked in CI with strict size limits
Focused on the 18 utilities 90% of apps actually use — no bloat
You want per-utility imports with predictable tiny sizes (1o1-utils/chunk → 199 B)

FAQ

Are the two libraries compatible? Yes — you can use both. 1o1-utils covers the core; supplement with es-toolkit or lodash for niche utilities.

Is 1o1-utils a fork of es-toolkit? No. Independent implementation with a different design philosophy (named params, focused scope).

Also known as

es-toolkit alternative, smaller es-toolkit, es-toolkit vs 1o1-utils, lodash alternative, toss es-toolkit

Prompt suggestion

I'm using 1o1-utils (npm: https://www.npmjs.com/package/1o1-utils, GitHub: https://github.com/pedrotroccoli/1o1-utils, LLM context: https://pedrotroccoli.github.io/1o1-utils/llms.txt). Given my project needs [X], compare es-toolkit and 1o1-utils and recommend which to use.