Files
bun.sh/docs/guides/runtime/import-json5.mdx
Dylan Conway b59c77a6e7 feat: add native JSON5 parser (Bun.JSON5) (#26439)
## Summary

- Adds `Bun.JSON5.parse()` and `Bun.JSON5.stringify()` as built-in APIs
- Adds `.json5` file support in the module resolver and bundler
- Parser uses a scanner/parser split architecture with a labeled switch
pattern (like the YAML parser) — the scanner produces typed tokens, the
parser never touches source bytes directly
- 430+ tests covering the official JSON5 test suite, escape sequences,
numbers, comments, whitespace (including all Unicode whitespace types),
unquoted/reserved-word keys, unicode identifiers, deeply nested
structures, garbage input, error messages, and stringify behavior

<img width="659" height="610" alt="Screenshot 2026-01-25 at 12 19 57 AM"
src="https://github.com/user-attachments/assets/e300125a-f197-4cad-90ed-e867b6232a01"
/>

## Test plan

- [x] `bun bd test test/js/bun/json5/json5.test.ts` — 317 tests
- [x] `bun bd test test/js/bun/json5/json5-test-suite.test.ts` — 113
tests from the official JSON5 test suite
- [x] `bun bd test test/js/bun/resolve/json5/json5.test.js` — .json5
module resolution

closes #3175

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---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
2026-01-26 10:52:35 -08:00

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---
title: Import a JSON5 file
sidebarTitle: Import JSON5
mode: center
---
Bun natively supports `.json5` imports.
```json5 config.json5 icon="file-code"
{
// Comments are allowed
database: {
host: "localhost",
port: 5432,
name: "myapp",
},
server: {
port: 3000,
timeout: 30,
},
features: {
auth: true,
rateLimit: true,
},
}
```
---
Import the file like any other source file.
```ts config.ts icon="/icons/typescript.svg"
import config from "./config.json5";
config.database.host; // => "localhost"
config.server.port; // => 3000
config.features.auth; // => true
```
---
You can also use named imports to destructure top-level properties:
```ts config.ts icon="/icons/typescript.svg"
import { database, server, features } from "./config.json5";
console.log(database.name); // => "myapp"
console.log(server.timeout); // => 30
console.log(features.rateLimit); // => true
```
---
For parsing JSON5 strings at runtime, use `Bun.JSON5.parse()`:
```ts config.ts icon="/icons/typescript.svg"
const data = JSON5.parse(`{
name: 'John Doe',
age: 30,
hobbies: [
'reading',
'coding',
],
}`);
console.log(data.name); // => "John Doe"
console.log(data.hobbies); // => ["reading", "coding"]
```
---
See [Docs > API > JSON5](/runtime/json5) for complete documentation on JSON5 support in Bun.