Browse free open source JavaScript Libraries and projects below. Use the toggles on the left to filter open source JavaScript Libraries by OS, license, language, programming language, and project status.

  • Train ML Models With SQL You Already Know Icon
    Train ML Models With SQL You Already Know

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  • 1

    Nan.System.Scripts

    System-level script objects (JavaScript)

    Nan.System.Scripts ver. 1.1.0-alpha The Nan.System.Scripts solution provides helper objects in JavaScript. NOTE: This is an alpha version and the public interfaces may change. CHANGES: v.1.1.0-alpha: finalized cloner/extender, fixed several bugs, extended test coverage.
    Downloads: 0 This Week
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  • 2
    NativeUI

    NativeUI

    The most crossbrowser web UI library that uses native browser elements

    NativeUI is a CSS and JavaScript library that adheres to the KISS principle and focuses on utilizing standard features provided by browsers, which are most optimized for each specific platform, and therefore provide the best performance and user experience. The library ensures cross-browser behavior and styling of built-in browser elements of user interface and text formatting, adding commonly used user interface elements such as modal windows, image viewer, menus, tabs, form messages, etc. It also contains some useful JavaScript functions for development, such as request() and getFormData(). You can see the demo here: https://nativeui.sourceforge.io/
    Downloads: 0 This Week
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  • 3
    NiL.JS

    NiL.JS

    JavaScript engine for .NET written in C#

    NiL.JS is a JavaScript engine written in C#, capable of executing ECMAScript 6.0 (ES2015) code. It allows embedding JavaScript execution within .NET applications, providing a bridge between C# and JavaScript.​
    Downloads: 0 This Week
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  • 4

    NiceScrollbars

    Javascript library to create fully css styleable scrollbars

    This Javascript library allows you to replace operating system dependent scrollbar elements with something that you can fully style using CSS rules while you still get the standard, usual behaviour on different platforms like desktop computers, smart phones and touch screen based tablets. Library supports <DIV>, <TEXTAREA> and multiple <SELECT> elements. Please visit project website to download the code!
    Downloads: 0 This Week
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  • MongoDB Atlas runs apps anywhere Icon
    MongoDB Atlas runs apps anywhere

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  • 5
    Nightmare

    Nightmare

    A high-level browser automation library

    Nightmare is a high-level browser automation library from Segment. The goal is to expose a few simple methods that mimic user actions (like goto, type and click), with an API that feels synchronous for each block of scripting, rather than deeply nested callbacks. It was originally designed for automating tasks across sites that don't have APIs, but is most often used for UI testing and crawling. Segment started with an open source project. Since then, we’ve open sourced hundreds of our repos. We want to continue supporting the community by publishing our code and other developers’ awesome open source projects. We use these open source projects as the foundations of our infrastructure to handle billions of API calls per day and to allow us to rapidly build and test code on the client.
    Downloads: 0 This Week
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  • 6
    Node Crawler

    Node Crawler

    Web Crawler/Spider for NodeJS + server-side jQuery

    Most powerful, popular and production crawling/scraping package for Node, happy hacking.
    Downloads: 0 This Week
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  • 7
    Node.js Testing Best Practices

    Node.js Testing Best Practices

    Beyond the basics of Node.js testing

    This repository narrows the testing lens to Node.js backends, focusing on the challenges of servers, microservices, and cloud-native deployments. It covers API testing, contract testing, and persistence-layer strategies that avoid coupling tests to fragile implementation details. The material explains how to structure tests around process boundaries—HTTP, queues, cron jobs—while keeping fast feedback cycles through selective integration tests and reliable test doubles. It dives into topics like test containers, ephemeral databases, and idempotent fixtures to ensure deterministic runs in CI. Observability is treated as part of testing: logs, metrics, and tracing make failures diagnosable instead of mysterious. By aligning tests with service responsibilities instead of internal modules, the guide helps teams produce suites that reflect real production behavior.
    Downloads: 0 This Week
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  • 8
    NomeJS

    NomeJS

    Nome is a JavaScript library for location driven sites

    Nome (pronounced know me) is a JavaScript library that leverages the power of HTML5 geolocation and location data. This type of data isn't normally exposed within a user session without signing up to multiple services and installing many large database files locally. Nome gives direct access to location and weather data from an exposed JavaScript API allowing you to create context driven websites that deliver information relevant to your audience. With clever thinking nome has the potential to change the way you deliver content to your audience. A bar could show offers for cool drinks if the temperature rose above 25°c; A shop could entice with targeted offers to customers right outside their door. With nome giving access to more information than is currently offered from a standard browser session, you or your clients could be engaging customers in a new way.
    Downloads: 0 This Week
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  • 9
    Numeral.js

    Numeral.js

    A javascript library for formatting and manipulating numbers

    You can use Numerals in the browser and in Node.js. Create an instance of a numeral, Numeral takes numbers or strings that it trys to convert into a number. Numbers can be formatted to look like currency, percentages, times, or even plain old numbers with decimal places, thousands, and abbreviations. And you can always create a custom format. Set a default format so you can use .format() without a string. The default format to '0,0'. Set a custom output when formatting numerals with a value of 0 or null. Adding your own custom formats is as easy as adding a locale. Numeral.js, while less complex, was inspired by and heavily borrowed from Moment.js Formats now exist in their own files and act more or less as plugins. Check out the bytes format for an example of how to create one. When naming locale files use the ISO 639-1 language codes supplemented by ISO 3166-1 country codes when necessary.
    Downloads: 0 This Week
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  • 8 Monitoring Tools in One APM. Install in 5 Minutes. Icon
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  • 10
    The Open Source Mobile Widget Platform is an Orange initiative to bring a complete software stack (client and server side) for distribution of mobile widgets on Java feature phones. http://www.orange.com/fr_FR/presse/communiques/cp101001fr2.jsp
    Downloads: 0 This Week
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  • 11
    Oboe.js

    Oboe.js

    A streaming approach to JSON

    Oboe.js is a streaming approach to JSON. Oboe.js speeds up web applications by providing parsed objects before the response completes. Oboe.js is an open source Javascript library for loading JSON using streaming, combining the convenience of DOM with the speed and fluidity of SAX. It can parse any JSON as a stream, is small enough to be a micro-library, doesn't have dependencies, and doesn't care which other libraries you need it to speak to. We can load trees larger than the available memory. Or we can instantiate classical OOP models from JSON, or completely transform your JSON while it is being read. Oboe makes it really easy to start using json from a response before the ajax request completes. Or even if it never completes.
    Downloads: 0 This Week
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  • 12
    Ohm

    Ohm

    A library and language for building parsers, interpreters, compilers

    Ohm is a parsing toolkit consisting of a library and a domain-specific language. It allows developers to define grammars and build parsers, interpreters, and compilers with ease, facilitating language design and processing tasks.​
    Downloads: 0 This Week
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  • 13
    OnlineToolsBook

    OnlineToolsBook

    Online tool cheats, write a high-quality manual for online tools

    OnlineToolsBook positions itself as a “manual/handbook” for useful online tools — collating, documenting, and explaining many web-based utilities to help users discover, understand, and effectively use them. Rather than building a single web-tool, this repository serves as a knowledge base: descriptions, guidance, and possibly examples or usage notes about a variety of online tools, organized in a way that’s meant to help “make online tools benefit humanity.” For someone who frequently resorts to ad-hoc web tools to solve tasks (text manipulation, image processing, conversion, utilities), OnlineToolsBook acts as an aggregator of “cheat sheets” or curated pointer collection rather than a specific application. The intention appears to be long-term: the repository can be updated to reflect new tools, remove broken ones, organize categories, or provide usage hints — so it becomes a living, crowd-maintained reference.
    Downloads: 0 This Week
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  • 14
    Open Airline Revenue Accounting
    That project aims at delivering a reference implementation of a library, estimating and serving average prices paid for air travel products. It is not intended for use by an actual airline, but rather by simulators or other airline-related modules of
    Downloads: 0 This Week
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  • 15
    Opensource

    Opensource

    Delivering delightful digital solutions

    This repository by tunnckoCore serves as a hub for various open-source projects and initiatives. It includes tools, libraries, and resources aimed at improving developer workflows and promoting open-source collaboration.​
    Downloads: 0 This Week
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  • 16
    OrgChart

    OrgChart

    It's a simple and direct organization chart plugin

    It's a simple and direct organization chart plugin. Anytime you want a tree-like chart, you can turn to OrgChart.
    Downloads: 0 This Week
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  • 17
    PDF API HTML5 Web Apps

    PDF API HTML5 Web Apps

    Mini SDK JavaScript API library PDF web apps

    A condensed library designed to web modern applications, to quickly export your content html to pdf thanks the famous library in javascript: jsPDF. And a special thanks to the project canvg and html2canvas. Project documentation: http://ulmdevice.altervista.org/pdfapihtml5/#documentation ========== Also available service for Angular 7+: http://ulmdevice.altervista.org/pdfjsapi/ Mobile Applications: http://bit.ly/1MrlgKk Opera add-on: http://bit.ly/1kkMhTa
    Downloads: 0 This Week
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  • 18
    PHP4sack
    A PHP encapsulation of the AJAX sack library so that developers need only code in PHP to implement AJAX, Feedback will be good to improve this component set. Now supporting cross browser drag and drop events, no other library dependencies.
    Downloads: 0 This Week
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  • 19
    ParkerIgniter
    This is a component to create dinamic database queries from a check list view. You can set a db object (views/tables/etc) to select columns to be shown in the main checklist to build a query based in the check selection. Add dinamic (sql) or static HTML selects to filter results through wheres with few lines. Create dinamic XLSX reports easily (XLSXWritter)
    Downloads: 0 This Week
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  • 20
    Parsley

    Parsley

    Validate your forms, frontend, without writing a line of javascript

    Parsley, the ultimate JavaScript form validation library. Validating forms frontend have never been so powerful and easy. Like no other form validation library, simply write in English your requirements inside your form HTML tags, Parsley will do the rest! No need to write even a single JavaScript line for simple form validation. Parsley is now smarter, it automatically detects your forms' modifications and adapts its validation accordingly. Simply add, remove or edit fields, Parsley validation will follow! Parsley is shipped with more than a dozen useful validators. If not enough, use the awesome Parsley extra Ajax validator or tons of other extended validators provided by the community. Parsley strongly focuses on #UI and #UX. Override almost every Parsley default behavior to fit your exact needs. Still ships almost bug free. Parsley is strongly tested, and aims to work on every browser (including IE8).
    Downloads: 0 This Week
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  • 21

    PassJS

    Giving a Cross-Browser JavaScript

    This library tries to hide differences between JavaScript implementations across browsers. This library is Licenced under the GNU GPLv3 Licence.
    Downloads: 0 This Week
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  • 22
    PathFinding.js

    PathFinding.js

    A comprehensive path-finding library for grid based games

    The aim of this project is to provide a path-finding library that can be easily incorporated into web games. It may run on Node.js or the browser. It comes along with an online demo to show how the algorithms execute. (The pathfinding speed is slowed down in the demo). Note that this project only provides path-finding algorithms for 2D space. If you need to work in a 3D environment, then you may use @schteppe's fork. When instantiating path-finders, you may pass in additional parameters to indicate which specific strategies to use. For all path-finders, you may indicate whether diagonal movement is allowed. The default value is false, which means that the path can only go orthogonally. When diagonal movement is enabled, you might want to prevent the path from touching the corners of the occupied grid blocks. This is usually desirable if the objects using the path have physical width and can also move between the grid cells.
    Downloads: 0 This Week
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  • 23
    Permit

    Permit

    An unopinionated authentication library for building Node.js APIs

    This project is an unopinionated authentication library for Node.js APIs that focuses on adding an auth layer without forcing a specific framework or application style. It’s built to slot into popular server stacks like Express, Koa, Hapi, or Fastify, and it stays compatible with different API styles including REST and GraphQL. The library concentrates on the core authentication schemes many APIs need, including bearer token authentication and basic username/password credentials. It also supports pulling credentials from common request locations, prioritizing standards-based headers while allowing practical alternatives when needed. The design aims to keep authentication logic centralized and consistent, so you avoid copy-pasting auth checks across handlers and middleware. In short, it provides a small, reusable abstraction for authenticating requests that you can adapt to your project’s policies and user model.
    Downloads: 0 This Week
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  • 24
    Phaser Raycaster

    Phaser Raycaster

    Raycasting plugin for Phaser 3

    Phaser Raycaster is a plugin for Phaser 3 that implements raycasting functionality, enabling developers to simulate visibility, lighting, and field-of-view mechanics in their games.
    Downloads: 0 This Week
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  • 25
    PhotoJShop

    PhotoJShop

    Photo editing JavaScript library

    PhotoJShop is a JavaScript library for photo editing using the canvas and kernel convolution matrixes, aiming to reproduce the most usual filters. A demo of its capabilities can be seen in Nuophoto, a project that uses this library for all the editing. The idea is to provide a simple library to developers that will allow quick integration of photo filters to their website. After including jQuery, include photojshop.jquery.js. Once loaded you simply need to call it on a valid element. You have to ensure that the element has loaded, $(document).ready() doesn't mean images have loaded.
    Downloads: 0 This Week
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