Documentation

FLASH.js is familiar by design — if you know $(".card").addClass("active"), you know F(".card").addClass("active"). Underneath it's all modern Web APIs, ESM-first and tree-shakable.

ESM-FirstZero deps~6—8 KB gzipTypeScript

Dogfooding: This site itself is built with FLASH.js — nav, search, theme, toasts, copy, modals and every interactive demo run on the real library. Open DevTools, no jQuery.

Start here

Getting Started →

Install via npm or CDN, first F() call, ESM vs UMD.

Core →

F(), selectors, collections, chaining, F.ready.

DOM →

html/text/val, classes, attributes, css, traversal.

Events →

on/off/one/trigger + delegation.

HTTP →

F.http.json, timeout, AbortController.

UI →

toast, modal, alert, confirm, loading.

Quick example

import { F } from "flash.js";

F(".button")
  .addClass("active")
  .on("click", () => F.toast("Hello, FLASH.js!", "success"));

— real F.toast

Modules

Tree-shaking via sideEffects: false and subpath exports:

import { http } from "flash.js/http";   // only http
import { toast } from "flash.js/ui";      // only ui
import { F } from "flash.js";             // core + attached helpers

See Modules / Tree-shaking for full export map and Rollup/Vite setup.

Migration

Coming from jQuery? Migration guide maps $ → F side-by-side, explains philosophy, ESM and what is intentionally different.