# Bun Check if two objects are deeply equal

> Check if two objects are deeply equal

- Skill: `jarle/bun-check-if-two-objects-are-deeply-equal` (Agent Skill)
- Install (CLI): `npx skillmds@latest add jarle/bun-check-if-two-objects-are-deeply-equal`
- Raw SKILL.md: https://api.skillmd.com/api/skills/jarle/bun-check-if-two-objects-are-deeply-equal/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: jarle (https://skillmd.com/u/jarle)
- Updated: 2026-09-21
- Page: https://skillmd.com/skills/jarle/bun-check-if-two-objects-are-deeply-equal

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# Check if two objects are deeply equal

Check if two objects are deeply equal. This is used internally by `expect().toEqual()` in Bun's [test runner](/test/writing-tests).

```ts index.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
const a = { a: 1, b: 2, c: { d: 3 } };
const b = { a: 1, b: 2, c: { d: 3 } };

Bun.deepEquals(a, b); // true
```

***

Pass `true` as a third argument to enable strict mode. This is used internally by `expect().toStrictEqual()` in Bun's [test runner](/test/writing-tests).

The following examples would return `true` in non-strict mode but `false` in strict mode.

```ts index.ts icon="https://mintcdn.com/bun-1dd33a4e/nIz6GtMH5K-dfXeV/icons/typescript.svg?fit=max&auto=format&n=nIz6GtMH5K-dfXeV&q=85&s=5d73d76daf7eb7b158469d8c30d349b0" theme={"theme":{"light":"github-light","dark":"dracula"}}
// undefined values
Bun.deepEquals({}, { a: undefined }, true); // false

// undefined in arrays
Bun.deepEquals(["asdf"], ["asdf", undefined], true); // false

// sparse arrays
Bun.deepEquals([, 1], [undefined, 1], true); // false

// object literals vs instances w/ same properties
class Foo {
  a = 1;
}
Bun.deepEquals(new Foo(), { a: 1 }, true); // false
```

***

See [Docs > API > Utils](/runtime/utils) for more useful utilities.