JavaScript Open Source Projects to Contribute To in 2026

The best JavaScript open source projects to contribute to are the ones you already use: Node.js, React, Vue, Svelte, Vite, Astro, ESLint, Prettier, Vitest, Hono, Three.js and MDN's docs repo are all active, permissively licensed, and publish contributor guides. This page lists 14 open source JS projects that were receiving commits in October 2026, the label each one uses for beginner-friendly issues, and a realistic first contribution for each. Below that: how to find open issues in JavaScript projects with GitHub search, and how to get a first pull request merged.

The list: open source JavaScript projects at a glance

Stars and licenses are from each project's GitHub repository as of October 2026, rounded. "Beginner label" is the label the maintainers actually use, which is the one to filter on.

Project	What it is	Language	License	Stars	Beginner label
Node.js	Server-side JS runtime	JS, C++	MIT	~122k	good first issue, help wanted
React	UI library	JS	MIT	~251k	good first issue
Vue	UI framework (v3 core)	TS	MIT	~55k	good first issue, help wanted
Svelte	Compiler-based UI framework	JS	MIT	~88k	good first issue, help wanted
Vite	Dev server and build tool	TS	MIT	~83k	contribution welcome
Astro	Content-site framework	TS	MIT	~63k	good first issue, help wanted
ESLint	Linter	JS	MIT	~28k	good first issue, help wanted
Prettier	Code formatter	JS	MIT	~52k	help wanted
Vitest	Test runner	TS	MIT	~17k	good first issue, help wanted
Hono	Web framework on Web Standards	TS	MIT	~32k	help wanted
Three.js	3D graphics for the browser	JS	MIT	~116k	none; examples and docs PRs
Express	Node.js web framework	JS	MIT	~70k	good first contribution
MDN content	The docs at developer.mozilla.org	Markdown	CC-BY-SA 2.5 (prose), CC0 (newer code samples)	~11k	good first issue, accepting PR
freeCodeCamp	Learning platform and curriculum	TS	BSD-3-Clause	~457k	help wanted

A note on Bun, Deno and TypeScript: all three are open source and hugely popular, but their cores are no longer JavaScript. Bun and Deno are written mostly in Rust, and the TypeScript compiler in the microsoft/TypeScript repo is now mostly Go, so most open issues there need systems-language skills.

What to work on in each project

Big projects rarely have a "first issue" waiting for you. A realistic first contribution looks like this:

Node.js

Node has a large, well-documented process (CONTRIBUTING.md). Good entry points: missing test coverage for a core module, doc fixes in doc/api/, and reproducing bug reports on the latest release. Building Node from source takes a while the first time, so start with docs or tests in test/parallel/.

React, Vue and Svelte

The UI libraries have mature cores and few small issues. React marks the ones that exist with good first issue and moves them to good first issue (taken) once someone claims them. Where you can help sooner: confirm or reproduce bug reports (a minimal reproduction is valuable to maintainers), and improve the docs sites, which live in their own repos (reactjs/react.dev, vuejs/docs, and the documentation/ folder of the Svelte repo).

Vite, Vitest and Astro

The build-tool ecosystem is the most welcoming place for JavaScript contributors right now. Vite labels small tasks contribution welcome. Vitest and Astro both run on pnpm monorepos with clear setup steps in their contributing guides. Astro's docs and its Starlight theme (withastro/starlight) take many first-time PRs.

ESLint and Prettier

Formatter and linter bugs are concrete: "this input produces this wrong output." Prettier had dozens of open help wanted issues in October 2026, and each one comes with a minimal input you can turn into a test case. ESLint issues tend to be rule options and false positives.

Hono and Express

Hono is a small TypeScript codebase that runs on Cloudflare Workers, Deno, Bun, AWS Lambda and Node.js, among others (Hono docs). It's readable in an afternoon, which makes it good for a first contribution: middleware, adapters, docs. Express is older and changes slowly; it uses its own good first contribution label, and its contributing guide lives in the expressjs/.github repo.

MDN and freeCodeCamp

If you want to start with no build step at all, docs are the best way in. MDN's content repo is Markdown, and fixing a wrong example or an outdated compatibility note is a legitimate, reviewed contribution (MDN contribution guide). freeCodeCamp takes curriculum fixes and has its own contributor docs.

How to find open issues in JavaScript projects

GitHub's own guide lists the main routes: issue labels, topics pages, Trending, and Explore (GitHub Docs). In practice, labels plus a filter for "nobody assigned" gets you the furthest.

1. Search one repo's labels. Open the repo's Issues tab and search, for example:

   is:issue is:open no:assignee label:"good first issue"
   

   Swap in the label from the table above (contribution welcome for Vite, good first contribution for Express).

2. Search across projects with the GitHub CLI. This lists unassigned beginner issues in JavaScript or TypeScript repos owned by organizations you choose:

   gh search issues --label "good first issue" --state open --no-assignee \
     --owner vitejs --owner vitest-dev --owner withastro --owner eslint \
     --sort created --limit 20
   

   Without --owner or --repo the results are dominated by tiny repos, so always narrow it.

3. Use an aggregator. goodfirstissue.dev and up-for-grabs.net collect beginner issues from curated projects and let you filter by language.

4. Start from what breaks for you. The strongest first contributions are fixes for bugs you hit yourself, because you already have the reproduction.

One honest warning: in October 2026, several of the projects above had zero open, unassigned good first issue tickets. Those labels get claimed within hours, especially during Hacktoberfest. Don't wait for one to appear. Pick an open bug, comment that you're looking into it, and ask the maintainers whether a fix would be welcome.

How to get your first pull request merged

1. Read CONTRIBUTING.md first. It tells you the package manager (most of these use pnpm), how to run tests, the commit format, and whether you need to sign a CLA or DCO.
2. Comment on the issue before you code. Say what you plan to change. It avoids duplicate work and tells you early if the approach is wrong.
3. Reproduce it locally, ideally as a failing test. Most of these repos want a test with every bug fix.
4. Keep the PR small. One issue, one PR. Unrelated formatting changes slow review.
5. Run the project's checks (lint, type check, tests) before pushing. CI will run them anyway, and a red PR waits longer.
6. Respond to review, then wait. Maintainers are often volunteers. A polite ping after a week is fine; daily pings aren't.

On AI tools: many projects now ask contributors to disclose AI-generated code and reject unreviewed bulk PRs. Check the contributing guide, and only submit code you understand and have tested.

Smaller open source JS projects worth a look

Large projects teach you process; smaller ones get you merged faster. Browse open source developer tools that launched recently on DevHunt's open source tools page, and look for repos with recent commits, a CONTRIBUTING file and maintainers who reply to issues. For projects in other languages, see 10 open source projects to contribute to as a tools developer, and for JavaScript frameworks to build with, open source web frameworks compared.

FAQ

What are good JavaScript open source projects for beginners?

Docs repos (MDN content, Astro docs, framework docs sites) and mid-size tools with active maintainers, such as Vite, Vitest, Hono and Prettier. They have clear setup instructions, fast CI, and issues that come with a reproduction. Core React or Node.js work is possible but slower to land.

How do I find JavaScript open source projects on GitHub?

Use GitHub topic pages such as github.com/topics/javascript, Trending filtered by language, and issue search with label:"good first issue" restricted to repos or owners you care about. The gh search issues command above does the same from a terminal.

Do I need to know TypeScript to contribute to JavaScript projects?

For many of them, yes: Vue, Vite, Vitest, Astro and Hono are written in TypeScript. If you know modern JavaScript, reading TypeScript is quick to learn, and the type checker catches mistakes before review does.

Is contributing to open source worth it for a JavaScript developer?

It's the most public proof of skill you can get: reviewed code in a project employers recognize. You also learn how large codebases handle testing, releases and review. Start small; one merged fix teaches more than a stalled big feature.

Are these projects free to use in commercial products?

Everything in the table uses a permissive license (MIT, Apache-2.0 or BSD-3-Clause), which allows commercial use as long as you keep the license notice. MDN's prose is CC-BY-SA, which requires attribution and share-alike if you copy it.