toastr

Toastr is a JavaScript library for rendering short-lived, non-blocking notification messages — commonly called toasts — in the browser. Built as a jQuery plugin, it exposes a minimal API (toastr.success, toastr.info, toastr.warning, toastr.error) that lets any page trigger a styled popup without wiring up custom DOM or CSS. Toasts stack automatically, support configurable positioning (corners or center, top or bottom), and can be dismissed by timeout, click, or an optional close button.

The library ships as a single dependency-light file (toastr.js) alongside LESS/SCSS/CSS styling, making it easy to drop into legacy jQuery-based applications or any server-rendered stack (Rails, ASP.NET, PHP) that already loads jQuery. It has been a staple in enterprise and CRUD-heavy web apps for form-validation feedback and background-task status messages since 2012, though its jQuery dependency and light maintenance today mean it sees little active development.

What You Get

• Four built-in toast types (success, info, warning, error) with distinct icon styling
• Configurable positioning, animation, and timeout behavior via a single toastr.options object
• Optional close button, progress bar, and RTL layout support
• Prebuilt LESS, SCSS, and compiled CSS themes for quick styling customization

Common Use Cases

• Confirming a form submission or save action succeeded
• Surfacing validation errors without a full page reload
• Notifying users of background job or AJAX request completion
• Displaying session-timeout or authentication warnings in server-rendered apps

Under The Hood

Architecture Toastr is a single closure wrapped in a UMD shim (AMD define, CommonJS module.exports, or window.toastr global) that exposes one public object (clear, remove, error, info, success, warning, subscribe, options) backed by a shared internal notify() function; every public toast method funnels through it, builds jQuery-wrapped title/message/close/progress elements, and manages one lazily-created $container for all active toasts. There is no module system beyond this single file — internal helpers are grouped under a comment banner rather than separated into files — so the design favors a small, flat surface area over layered separation of concerns; changing notify()’s contract would ripple through every public method at once.

Tech Stack The only runtime dependency is jQuery (>=1.12.0), and the library is distributed as a UMD module supporting AMD, CommonJS, and global-script consumption. Styling is authored in both LESS and SCSS and compiled to CSS via a Gulp 3.x pipeline (gulp-less, gulp-minify-css, gulp-uglify, gulp-bytediff for build-size auditing). Continuous integration runs through Travis CI, and code style is enforced with JSHint and JSCS rather than a modern linter/formatter. There is no TypeScript, bundler, or build step required for consumers — just the compiled toastr.js/toastr.css files.

Code Quality A test suite exists (tests/unit/toastr-tests.js) written against QUnit and run through Karma with karma-phantomjs-launcher, covering show/hide/clear/prevent-duplicate behaviors reasonably thoroughly for the library’s size. However PhantomJS and its Karma launcher have been unmaintained for years, so the configured CI path is unlikely to run cleanly on current Node/browser tooling. There is no type safety in the source (no bundled type definitions), error handling is minimal (no try/catch; the code assumes jQuery methods are always present), and naming conventions are consistent and readable throughout.

API Design Toastr’s public surface is deliberately tiny — four verb-named methods (success/info/warning/error) plus a single shared options object for every cross-cutting behavior (position, animation easing/duration, close button, progress bar, RTL). A subscribe hook exposes toast lifecycle events (shown/hidden) to calling code without extra ceremony. This pattern predates most modern toast libraries and requires almost no boilerplate to get a first toast on screen, though it also means there is no per-instance component API — all configuration is global mutable state on toastr.options.