Introduction
The landscape of web development has officially shifted. As of February 2026, the long-awaited TC39 Signals proposal has reached Stage 4, and the "State Management Wars" that defined the last decade of JavaScript development have come to an abrupt end. With the release of Chrome 146 and Safari 19.4 this month, native engine support for Signals is now a reality for over 90% of global users. We are no longer required to ship massive libraries like Redux, MobX, or even specialized hooks-based state managers to achieve fine-grained reactivity.
For years, developers relied on third-party abstractions to bridge the gap between static JavaScript objects and the dynamic requirements of modern UIs. Whether it was the Virtual DOM diffing of React or the compiler-heavy approach of Svelte 6 Runes, every solution came with a trade-off: bundle size, proprietary syntax, or runtime overhead. Native JS Signals eliminate these hurdles by moving the reactivity engine directly into the browser's C++ core. This means state updates now happen at the speed of the engine, not the speed of the library.
In this tutorial, we will explore why you should drop your external state management libraries in 2026. We will dive deep into the standardized Signal API, learn how to build framework-agnostic applications, and understand why the Chrome 146 update represents the most significant change to the JavaScript ecosystem since the introduction of Promises and Async/Await. If you are still importing createSlice or atom in 2026, you are writing legacy code.
Understanding Native JS Signals
Native JavaScript Signals are objects that represent a value that changes over time, coupled with a mechanism to notify consumers when that change occurs. Unlike standard variables, Signals keep track of their dependencies automatically. When you access a Signal inside a computation, the engine "remembers" that relationship, creating a graph of dependencies that updates efficiently and only when necessary.
This is often referred to as "fine-grained reactivity." In traditional frameworks, a state change often triggers a re-render of a large component tree. With Native JS Signals, a change to a single piece of state can update a single text node in the DOM without ever touching the surrounding elements. This performance profile matches or exceeds SolidJS Performance metrics but does so using standard, built-in browser APIs.
Key Features and Concepts
Feature 1: Signal.State
The Signal.State class is the fundamental building block of the new reactivity model. It holds a single value and provides get() and set() methods. Because it is a native class, it is highly optimized for memory usage and garbage collection, making it far more efficient than the Proxy-based objects used in older state libraries.
Feature 2: Signal.Computed
The Signal.Computed class allows you to create derived state. A computed signal will only re-calculate its value if the signals it depends on have changed. Furthermore, native computed signals are "lazy" by default; they do not perform any work until their value is actually requested by a watcher or another signal.
Feature 3: The Watcher API
The Signal.subtle.Watcher API is the "glue" between the state graph and the outside world. It allows developers to subscribe to changes in the signal graph to perform side effects, such as updating the DOM or making API calls. While the "subtle" namespace indicates it is a low-level API intended for framework authors, it is easily accessible for building lightweight, library-free applications.
Implementation Guide
Let us build a real-world implementation of a reactive system using nothing but native JavaScript. We will start with a basic counter and then move to a more complex data-fetching scenario.
// 1. Initialize native State signals
// No imports required in Chrome 146+
const count = new Signal.State(0);
const multiplier = new Signal.State(2);
// 2. Create a Computed signal for derived state
// This automatically tracks dependencies on 'count' and 'multiplier'
const total = new Signal.Computed(() => {
console.log("Computing total...");
return count.get() * multiplier.get();
});
// 3. Define an effect-like mechanism using the Watcher API
// The Watcher notifies us when any signal in our 'watch' list changes
const watcher = new Signal.subtle.Watcher(() => {
// This callback runs when dependencies are dirty
updateUI();
});
// Function to synchronize the DOM with our Signals
function updateUI() {
// Accessing values via .get()
document.getElementById('count-val').textContent = count.get();
document.getElementById('total-val').textContent = total.get();
// Re-subscribe the watcher to the signals we just accessed
// This is the standard pattern for native signal effects
watcher.watch(count, total);
}
// 4. Set up initial watch and event listeners
watcher.watch(count, total);
updateUI();
document.getElementById('increment').addEventListener('click', () => {
// Updating state via .set()
count.set(count.get() + 1);
});
document.getElementById('change-multiplier').addEventListener('click', () => {
multiplier.set(Math.floor(Math.random() * 10));
});
The example above demonstrates the core power of the TC39 Signals Proposal. We have created a fully reactive UI with zero dependencies. The total value is only re-computed when the UI actually needs it, and the browser handles the dependency tracking under the hood.
Next, let us look at how to handle more complex objects and collections, which was previously a major pain point requiring libraries like Immer or Redux Toolkit.
/**
* Advanced State Management with Native Signals
* Managing an array of objects (Todo List)
*/
class TodoStore {
// Use a State signal to hold the array
#todos = new Signal.State([
{ id: 1, text: "Learn Native Signals", completed: true },
{ id: 2, text: "Drop Redux", completed: false }
]);
// Computed signal for filtered results
filteredTodos = new Signal.Computed(() => {
return this.#todos.get().filter(t => !t.completed);
});
// Computed signal for statistics
stats = new Signal.Computed(() => {
const all = this.#todos.get();
return {
total: all.length,
remaining: all.filter(t => !t.completed).length
};
});
// Action to add a todo
addTodo(text) {
const current = this.#todos.get();
// We follow immutability patterns for best results with signals
this.#todos.set([...current, {
id: Date.now(),
text,
completed: false
}]);
}
// Action to toggle completion
toggleTodo(id) {
const updated = this.#todos.get().map(todo =>
todo.id === id ? { ...todo, completed: !todo.completed } : todo
);
this.#todos.set(updated);
}
}
// Usage in an application
const store = new TodoStore();
// A simple effect wrapper for the Watcher API
function createEffect(callback) {
const watcher = new Signal.subtle.Watcher(() => {
callback();
// Re-arm the watcher
watcher.watch();
});
// Initial run to collect dependencies
callback();
// Note: In a real implementation, you'd track what signals were accessed
}
createEffect(() => {
const { total, remaining } = store.stats.get();
console.log(<code>App State: ${remaining}/${total} tasks left</code>);
});
// Simulate user interaction
store.addTodo("Master Chrome 146 APIs");
store.toggleTodo(2);
</pre></code>
</div>
<p>In this second example, we see how Native JS Signals can encapsulate business logic within classes. This approach is highly compatible with Web Components, allowing for truly modular, framework-agnostic signals that can be shared across different micro-frontends regardless of their internal tech stack.</p>
<h2>Best Practices</h2>
<ul>
<ul><li><strong>Embrace Immutability:</strong> While signals can hold mutable objects, using immutable patterns (like the spread operator) when calling <code>.set()</code> ensures that the signal correctly identifies changes and triggers updates.</li>
<li><strong>Keep Computeds Pure:</strong> Always ensure that <code>Signal.Computed</code> functions are side-effect free. They should only calculate a value based on other signals. If you need to perform an action (like a network request), use a Watcher.</li>
<li><strong>Batch Your Updates:</strong> If you need to update multiple signals at once, try to group them. While native signals are efficient, updating them in a single tick prevents unnecessary intermediate computations.</li>
<li><strong>Memory Management:</strong> When using the Watcher API in a Single Page Application (SPA), ensure you call <code>watcher.unwatch()</code> when a component is destroyed to prevent memory leaks.</li>
<li><strong>Naming Conventions:</strong> Use clear names for your signals. Since they are no longer hidden behind a <code>useStatus</code> hook, naming them <code>userSignal</code> or <code>countState</code> helps distinguish them from standard variables.</li>
</ul></ul>
<h2>Common Challenges and Solutions</h2>
<h3>Challenge 1: Handling Asynchronous Data</h3>
<p>One common hurdle is how to represent an API request that is currently "loading." In 2026, the standard pattern is to use a signal that holds a state object representing the request status.</p>
<div class="code-block-wrapper">
<div class="code-block-header">
<span class="code-language-badge">JavaScript</span>
</div>
<pre><code class="language-javascript">
// Solution for Async Data with Signals
const userData = new Signal.State({ data: null, loading: false, error: null });
async function fetchUser(id) {
userData.set({ ...userData.get(), loading: true });
try {
const response = await fetch(<code>https://api.example.com/users/${id}</code>);
const data = await response.json();
userData.set({ data, loading: false, error: null });
} catch (error) {
userData.set({ data: null, loading: false, error: error.message });
}
}
// Computed signal to derive a display name
const userDisplayName = new Signal.Computed(() => {
const state = userData.get();
if (state.loading) return "Loading...";
if (state.error) return "Error loading user";
return state.data ? state.data.name : "No user selected";
});
Challenge 2: Integrating with Legacy Frameworks
If you are working in a React project in 2026 that hasn't fully migrated to native signals, you can bridge the gap using a custom hook. This allows you to use global native signals while still benefiting from React's component model.
// React 19+ Bridge for Native Signals
import { useState, useEffect } from 'react';
function useSignal(signal) {
const [value, setValue] = useState(signal.get());
useEffect(() => {
const watcher = new Signal.subtle.Watcher(() => {
setValue(signal.get());
watcher.watch(signal);
});
watcher.watch(signal);
return () => watcher.unwatch(signal);
}, [signal]);
return value;
}
// Component Usage
export function UserProfile({ globalUserSignal }) {
const user = useSignal(globalUserSignal);
return <div>Welcome, {user.name}</div>;
}
Future Outlook
The roadmap for Native JS Signals in 2026 and beyond is focused on even deeper integration with the browser. We are already seeing experimental proposals for HTMLSignalElement, which would allow developers to bind signals directly to HTML attributes in markup, completely bypassing the need for JavaScript-based DOM manipulation. This "HTML-first" reactivity will likely be the next major milestone after the TC39 proposal stabilizes across all engines.
Furthermore, the performance gap between "framework-heavy" and "native-only" apps will continue to widen. As Chrome 146 optimizes the internal dependency graph traversal in the V8 engine, apps built with native signals will enjoy faster startup times and lower memory footprints on mobile devices, making them the preferred choice for the next generation of progressive web apps.
Conclusion
The introduction of Native JavaScript Signals marks the end of an era. For over a decade, we treated state management as a problem that required external libraries to solve. In 2026, that problem has been moved into the language itself. By dropping state management libraries in favor of the TC39 Signals Proposal, you reduce your bundle size, improve your application's performance, and write code that is future-proof and standards-compliant.
The transition may require a mental shift—moving away from the Virtual DOM and toward fine-grained reactivity—but the rewards are undeniable. Start by refactoring your global stores into Signal.State and Signal.Computed. Experiment with the Watcher API to handle your side effects. As the ecosystem continues to evolve around the Chrome 146 update, you will find that the best library for state management is no library at all.