# node-json-logger > Simply, output logs to STDOUT in JSON Latest version **0.3.0** (published 2026-05-25) · MIT license · 0 weekly downloads ## Install ```sh npm install node-json-logger pnpm add node-json-logger yarn add node-json-logger bun add node-json-logger ``` ## Health **Score 58/100 (C)** — status: active. Positive: has types package; no vulnerabilities; high maintenance score; high quality score. Warnings: low downloads; no esm support; pre 1.0. ## Facts | | | |---|---| | Version | 0.3.0 | | Published | 2026-05-25 | | First published | 2018-02-24 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | separate (@types/node-json-logger) | | Module format | CommonJS | | Node | >=22 | | Dependencies | 1 | | Unpacked size | 20.2 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 7 | | Author | hidori | | Maintainers | hidori | | Keywords | logger, json | ## Links - npm: https://www.npmjs.com/package/node-json-logger - Repository: https://github.com/hidori/node-json-logger - Homepage: https://github.com/hidori/node-json-logger#readme - Issues: https://github.com/hidori/node-json-logger/issues - npm.io page: https://npm.io/package/node-json-logger ## Dependencies (1) - [moment-timezone](https://npm.io/package/moment-timezone.md) ^0.5.43 ## Alternatives - [@mapbox/jsonlint-lines-primitives](https://npm.io/package/@mapbox/jsonlint-lines-primitives.md) — 5.3M weekly downloads - [reftools](https://npm.io/package/reftools.md) — 3.5M weekly downloads - [@hey-api/openapi-ts](https://npm.io/package/@hey-api/openapi-ts.md) — 3.5M weekly downloads - [@mapbox/geojson-rewind](https://npm.io/package/@mapbox/geojson-rewind.md) — 2.4M weekly downloads - [turbo-stream](https://npm.io/package/turbo-stream.md) — 1.7M weekly downloads ## Recent versions - 0.3.0 (latest) — 2026-05-25 - 0.2.1 — 2024-02-11 - 0.2.0 — 2023-12-16 - 0.1.3 — 2023-06-17 - 0.1.2 — 2023-06-02 - 0.1.1 — 2023-06-02 - 0.1.0 — 2023-02-01 - 0.0.19 — 2022-12-29 - 0.0.18 — 2022-06-25 - 0.0.17 — 2021-06-01 - 0.0.16 — 2021-05-18 - 0.0.15 — 2021-05-05 - 0.0.14 — 2021-05-05 - 0.0.13 — 2021-04-07 - 0.0.12 — 2021-01-05 - … 10 more at https://npm.io/package/node-json-logger/versions ## README [![Software License](https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square)](LICENSE) [![Build Status: CI](https://github.com/hidori/node-json-logger/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/hidori/node-json-logger/actions/workflows/ci.yml?query=branch%3Amaster) [![Maintainability](https://api.codeclimate.com/v1/badges/1dd1bfe212c8d70c9b8b/maintainability)](https://codeclimate.com/github/hidori/node-json-logger/maintainability) # node-json-logger Simply, output logs to STDOUT in JSON ## Install ```sh npm i node-json-logger ``` ## Usage ```js const Logger = require('node-json-logger'); const logger = new Logger(); logger.info(); logger.info('message'); logger.info('message','message','message'); logger.info({ data: 'data' }); logger.info({ data1: 'data' }, { data2: 'data' }); logger.info('message', { data1: 'data' }, 'message', { data2: 'data' }, 'message'); ``` Outputs: ```json {"timestamp":"2001-03-14T01:00:00.000Z","level":"info"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message","message1":"message","message2":"message"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","data":"data"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","data1":"data","data2":"data"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","message":"message","data1":"data","message1":"message","data2":"data","message2":"message"} ``` ## API ```js logger.xxx(message?, ...) ``` Note: * xxx is one of the [Levels](#Levels) Arguments: * message: Specify a message as string or object. ## Levels * trace * debug * info * warn * error * fatal ## Configuration ### level Specify output level. (optional, default is `debug`) ```js const Logger = require('node-json-logger'); const logger = new Logger({ level: 'error'}); logger.trace('message'); logger.debug('message'); logger.info('message'); logger.warn('message'); logger.error('message'); logger.fatal('message'); ``` Output: ```json {"timestamp":"2001-03-14T01:00:00.000Z","level":"error","message":"message"} {"timestamp":"2001-03-14T01:00:00.000Z","level":"fatal","message":"message"} ``` Level and output: | | trace | debug | info | warn | error | fatal | |:---------------------|:------|:------|:-----|:-----|:------|:------| | `{ level: 'trace' }` | O | O | O | O | O | O | | `{ level: 'debug' }` | - | O | O | O | O | O | | `{ level: 'info' }` | - | - | O | O | O | O | | `{ level: 'warn' }` | - | - | - | O | O | O | | `{ level: 'error' }` | - | - | - | - | O | O | | `{ level: 'fatal' }` | - | - | - | - | - | O | | `{ level: 'none' }` | - | - | - | - | - | - | ### loggerName Specify the name of the logger. Useful when logging from different files. ```js const Logger = require('node-json-logger'); const logger = new Logger({ loggerName: 'server/index.js' }); logger.info('message'); ``` Output: ```json {"timestamp":"2001-03-14T01:00:00.000Z","level":"info","loggerName":"server/index.js","message":"message"} ``` ### timestamp Specify enable or disable timestamp. (optional, default is true) ```js const Logger = require('node-json-logger'); const logger = new Logger({ timestamp: false }); logger.info('message'); ``` Output with disabled timestamp: ```json {"level":"info","message":"message"} ``` ### timezone Specify locale timezone. (optional, default is UTC) ```js const Logger = require('node-json-logger'); const logger = new Logger({timezone: 'America/Sao_Paulo'}); logger.info('message'); ``` Output with specific timezone: ```json {"timestamp":"2018-10-25T15:32:43.318Z","level":"info","message":"message"} ``` Same output with default timezone (UTC): ```json {"timestamp":"2018-10-25T18:32:43.318Z","level":"info","message":"message"} ``` [Click here](https://momentjs.com/timezone/) to see the list with all available timezones. ## License MIT Copyright ©2018 Hiroaki SHIBUKI a.k.a. [hidori](https://github.com/hidori) --- _Source: https://npm.io/package/node-json-logger · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._