Introduction
What is Fastjs?
Fastjs (npm: jsfast) is a tiny, zero-dependency JavaScript toolkit. It bundles a small set of utilities that show up in almost every front-end project — DOM manipulation, HTTP requests, date formatting, cookies, and a few general-purpose helpers — behind a single, consistent, type-safe API.
It works the same way in browsers and in Node.js (≥ 18), and is friendly to bundlers (tree-shakeable, no global side-effects, separate dev / prod builds).
Why Fastjs?
Most modern projects end up gluing together a handful of small libraries: one for AJAX, one for dates, one for selectors, one for clipboard… Each has its own conventions, types, and quirks.
Fastjs replaces the most common 10–20% of those libraries with one consistent surface:
- One package, one mental model. Every Fastjs instance (DOM element, date, request, cookie) is produced by the same internal factory, so they all share helpers like
setCustomProp,setCustomEvent,then, and they all chain. - Type-first. Public APIs ship full TypeScript types. Generics let you keep the underlying
HTMLInputElement, the response shape of an HTTP call, etc. - Modular. Import only what you need –
import { dom, rand } from "jsfast"will tree-shake everything else away. - Honest about environments. Browser-only modules (
dom,cookie,copy) degrade safely outside a browser instead of throwing on import.
Why not other libraries?
We considered the needs of users from many angles. Some of the recurring pain points other libraries cause:
Installation
Adding several small libraries each with their own deps adds up. Fastjs is one package that covers the basics.
API design
Tools that share concepts (e.g. selectors and Ajax) often expose them very differently. Fastjs uses one chainable, return-this pattern everywhere.
TypeScript support
We provide complete TypeScript declarations bundled with the package – you won't need @types/... packages.
Environment support
Fastjs is built to run anywhere modern: bundlers, browsers (IIFE / native ESM), Node.js (CJS / ESM). Where features need a browser API, the function degrades gracefully instead of throwing.
Module overview
| Module | Description |
|---|---|
dom | Select / build / manipulate DOM elements. FastjsDom, FastjsDomList. |
date | Parse / format dates, FastjsDate instance with timezone and "active time" support. |
request | Lightweight fetch wrapper with hooks, path params, debounce, cancellation. |
cookie | Safe browser cookie read / write with SameSite, Max-Age, scoped instances. |
utils | Random number / string / UUID, clipboard copy, polling, error helpers, type guards. |
FastjsModuleBase | Methods every Fastjs instance inherits. |
Goals
We build Fastjs because the JavaScript ecosystem is over-served by very similar small libraries — each with its own way of naming things, its own dependency tree, and its own quirks.
Our goal is to provide a single, uniform library that:
- Works the same way in Node.js and the browser.
- Has a smaller learning curve than learning four separate libraries.
- Lets you reach for "the standard thing" without re-evaluating dependencies every time.
Contributors
Thanks to these wonderful people for helping make Fastjs better 🙌
Sponsors
