React context prevent re render. Aug 27, 2025 · I will teach you how to prevent React.

React context prevent re render memo will indeed prevent component a from re-rendering. The full guide also includes the most important patterns that can help prevent re-renders and a few anti-patterns that lead to unnecessary re-renders and poor performance as a result. What I can't tell is whether every time I load 10 new top level components, will the existing top level comments re-render or will memo prevent them from re-rendering? Let's say I load "replies" to an existing comment that is at depth 4. As a best practice, always measure the impact of the changes you make. To memoize a component, wrap it in memo and use the value that it returns in Mar 31, 2023 · 0 According to React doc, useMemo and useCallback help performant optimization because comparison between rendering works correctly. I would like to prevent the re-rendering and only re-render the component that actually changes. To mitigate this, developers often use React. Oct 18, 2021 · Standard rendering and memo By default, when the state of a component changes, that component and all its children re-render. Memoizing Components with React. memo React. Strategies to Optimize Re-rendering 2. By understanding the causes of re-renders and adopting the techniques discussed—like memoization, breaking down large components, and optimizing context usage—you can drastically reduce the number of re-renders and improve your app's performance. Sep 4, 2022 · This is a very common performance problem while using the Context API. Dec 19, 2022 · I ran into this because I was filtering my data inside my functional react component, which caused the list to change, causing the table to change, causing a re-render. memo will re-render the component when its props change. But I still have a unsolved issue here (maybe I couldn't find some). Recap of using Context Let's quickly look at some code t Prevent re-render on global state update Now that we know how React renders our components let's check a more advanced example. Context import R Yeah, just set up a basic context and followed the good practice of creating a context provider component to prevent all components re-rendering when a context changes meaning just the components using the context re-render. In this blog, we’ll explore how to prevent unnecessary re In this video, we will look into when a React component actually re-renders. Apr 30, 2025 · 🔧 Controlling and Optimizing Re-renders While React does an excellent job optimizing re-renders, there are still scenarios where unnecessary re-renders can hurt performance. js components from unnecessary re-renders when the data changes, when using React Context API in your React. memo to prevent child components from re-rendering unnecessarily. This works: export default function About() { This causes infinite re-renders on context update: export default async function About() { Both are maked as "use client"; Expected Jun 3, 2024 · The Problem: Unnecessary Re-renders Traditionally, in React, when a parent component's state changes, all its child components re-render, regardless of whether their props have changed. Mar 19, 2025 · Learn how to optimize React Context for performance and avoid common re-rendering pitfalls. Any component bound to the context will be re-render when it changes - otherwise how is it supposed to have the new context state? May 9, 2025 · 2. Understanding Re-renders: The Foundation Before we optimize, we need to understand when and why React Sep 23, 2023 · To not Make this article very long, I will write another article about how to deal with re-rendering in React and what techniques you can use to prevent re-rendering in React. What can I do to avoid this? Split the contexts This is the preferred approach and consists of passing your variables that change too often to another context. This makes sense as Context is meant to share state between components rather than passing them down. So let’s dive in and see what happens with child components when their parents re-render. This article outlines best practices for beginners to minimize unnecessary re-renders and enhance the Oct 14, 2020 · 0 I made a simple react application with context as the state management, however, the default behavior of this context is always re-rendering every state even though the changes made only for one state. In my understanding, however, whenever parent component re-renders, its child components also re-render. Aug 29, 2022 · When using React Context prevent re-render of child components that don't need the new context value Asked 3 years, 2 months ago Modified 3 years, 2 months ago Viewed 531 times Mar 18, 2024 · Using React's Context API can help optimize child components by providing a way to pass down state without re-rendering all components in the hierarchy. Apr 9, 2023 · React : How to use context and prevent a re render from each item in a list when action is dispatched and new data is received only for specific item? Asked 2 years, 3 months ago Modified 2 years, 3 months ago Viewed 223 times Jun 4, 2023 · Why re-render only happens when state defined in the Provider wrapper component changes, not when value supplied to Context. Is React useState hook causing too many re-renders? React shouldComponent may help reduce or avoid the same child component to re-render multiple times. Understanding when and why React components re-render is key to… Feb 26, 2025 · Learn how to identify and fix common causes of infinite re-renders in React applications with practical examples and solutions Sep 23, 2021 · Improve your React app's performance by eliminating unnecessary re-renders with React Tracked, a library for state usage tracking. By separating your state and setter functions into different contexts, you can ensure components only rerender when the specific data they consume changes. current behaviour: whenever I add a new toast, existing ones get re rendered. This can lead to … Feb 1, 2025 · When a parent component’s state or props update, React triggers a re-render for the parent and all of its children by default. Aug 8, 2022 · The guide explains what are re-renders, what is necessary and unnecessary re-render, what can trigger a React component re-render. For now, we’ll focus on the first two phases. Oct 13, 2021 · Changes to the context value will rerender all of the consumers, because React simply does an === comparison on the updated values, and you're creating the object inline (so it's different each time). memo or shouldComponentUpdate to memoize components and prevent unnecessary re-renders. We will tackle this problem by asking several important questions Oct 5, 2024 · By using React Context, the theme state is managed globally, and changes to the theme will only re-render components that specifically consume the ThemeContext, preventing unnecessary re-renders of other components like HomePage. js applications. This article covers context splitting, memoization techniques, and the selector pattern to build more efficient and scalable React applications. What I want is, since I'm in development right now, is to request once, use that data even when I change/re-render my component/s. Feb 12, 2023 · In this blog post, we'll explore why this issue occurs and how you can avoid it by creating two separate contexts in your React app. Feb 8, 2022 · Comprehensive guide on React re-renders. This article explains how to reduce re-renders and avoid common pitfalls. memo May 24, 2022 · I found using useCallback to wrap my context's state updater methods resolved this question's issue for me. I have looked at using React. 1 React. Jun 3, 2024 · The Problem: Unnecessary Re-renders Traditionally, in React, when a parent component's state changes, all its child components re-render, regardless of whether their props have changed. For example, if the user is typing into an input faster than a chart receiving its deferred value can re-render, the chart will only re-render after the user stops typing. When building React applications, re-renders can impact performance, especially when dealing with expensive computations or large lists. These tools allow us to optimize our code by avoiding unnecessary re-renders, improving performance, and storing values efficiently. Every pattern and antipattern is accompanied by a visual 59 I have a component that consists of several other components such as text fields, and when an input is made to the text field, all other components are re-rendered. The most commons are Redux, mobx and context. so in your scenario, if the app re-renders but the props of component a remain unchanged, react. Luckily, there are several ways to control and optimize the rendering behavior in React apps. Optimize parent component rendering to avoid triggering unnecessary child component re-renders. With memo, you can create a component that React will not re-render when its parent re-renders so long as its new props are the same as the old props. If a component is wrapped in React. re-rendering within React. Sep 12, 2023 · This is not actually true. The React docs call this out specifically under the Generally yes unless you specifically arrange things to prevent that, because React re-renders recursively by default. This is easy to test by slapping a provider at the root level and putting some console logs in the sub tree to track re-renders, only components that actually use the context will re-render on context state change. memo, useMemo, and useCallback, avoiding inline functions and objects in JSX, optimizing context usage, and utilizing profiling tools. React starts the render process with whatever component queued a state update, then loops through all children below that component and renders them. or when I delete one toast, rest of them don't re render. Jun 19, 2023 · Click on URL to about page Click on button Describe the Bug Using context in page components causes infinite re-renders when updating context value if marked as async. 1. The background re-render is interruptible: if there’s another update to the value, React will restart the background re-render from scratch. memo() to prevent unnecessary re In this post we are going to prevent an unnecessary re-rendering when using Context API. Feb 26, 2024 · Stop Unnecessary Re-renders: Mastering the useCallback Hook in React React prides itself on efficiency, but sometimes, components can re-render even when they don’t need to. If it happens to be a problem to you, You can use React higher order component memo to memoize the Child component: Feb 9, 2022 · React Tracked: Manage State and Prevent Excessive Re-Rendering Over the last few years, state management in React has undergone a major evolution. Mar 31, 2025 · How React reacts? Every React component undergoes a series of lifecycle steps. Mar 22, 2022 · When the global context refreshes then it causes all the child components that consume the context to re-render. Sep 12, 2024 · Preventing unnecessary re-rendering in React involves a combination of strategies including memoization with React. Also includes most important patterns that can help prevent re-renders and a few anti-patterns that lead to unnecessary re-renders and poor performance as a result. memo() For functional components, you can use React. I have even tried to split the context and memoize components but nothing helps me. Prop Drilling vs. In this post we are going to prevent an unnecessary re-rendering when using Context API. Aug 19, 2021 · Context and React rendering From the first chapter, we know the default behavior of React rendering. If the cell id and context value match it will return <SelectedCell> otherwise <TableCell> Whenever the context is changed every cell in every row in every table is being re-rendered to check if the id matches. Feb 16, 2021 · Often with contexts I find myself using the context values directly within that component. My state updating methods were being re-evaluated on every re-render when any of the context's state was modified. For example: suppose there's a toplevel Sep 25, 2024 · When building React applications, re-renders are a common occurrence, but they can sometimes seem mysterious or even frustrating. Dec 27, 2022 · The reason is that React compares the old props with the new props which do not reference the same object, therefore React will re-render the child component. Feb 13, 2022 · I am struggling to prevent my whole app getting re-rendered. May 13, 2025 · Context Splitting in React: A Technique to Prevent Unnecessary Rerenders One of the most common issues developers face is managing rerenders, especially when working with Context API. Understanding and optimizing React's rendering behavior is crucial for creating fast and responsive applications. It allows you to create and manage a “global” state … Aug 21, 2019 · Thanks Daishi, I'm relatively new to react, and just encountered this problem of the entire app re-rendering because I'd changed the Context state value that shouldn't have that kind of impact. Is there a best practice to prevent all the cells from re-rendering? Jun 29, 2025 · This issue dives into optimizing React performance with insights on re-renders, Zero-UI for faster updates, and connecting to MCP servers. Let’s examine the following code: Jan 30, 2022 · Redundant re-renders are a common issue in React. Apr 17, 2021 · Fixing Re-Renders When Using Context in React Some months ago, I was refactoring a React project, and I was stuck in one problem for hours. Technical Background Core Concepts and Terminology React’s rendering process involves updating the virtual DOM whenever state or props change. The Context API is one of … Jul 23, 2025 · React's component-based architecture enables efficient UI updates, but developers often encounter challenges with unnecessary re-renders, which can hinder application performance. This recursion will go on until React throws a runtime error. memo to try and prevent the dropdown from re-rendering but can't get it to work. But it does mean hoisting state to a parent component just to prevent re-renders doesn't always make sense. Oct 2, 2023 · Understanding the mechanism behind React’s re-rendering process and optimizing performance. May 13, 2025 · Context splitting is a powerful technique for optimizing React applications that use the Context API. While React is highly optimized, unnecessary re-renders can still occur when parent components re-render, causing all child components to re-render as well, regardless of whether their props have changed. Jun 19, 2022 · How to prevent unnecessary re-rendering when using React Context. Jan 5, 2025 · React’s rendering works around state changes triggering re-renders, but unnecessary re-renders can severely impact performance, especially in applications with complex state dependencies. Such a component is said to be memoized. Apr 19, 2022 · I'm experiencing something similar to this: Should Custom React Hooks Cause Re-Renders of Dependent Components? So, I have something like this: const ComponentA = props =&gt; { const returnedValu Feb 21, 2021 · Learn how to use `useCallback` in JavaScript to avoid unnecessary re-renders and optimize your React application performance. Apr 19, 2022 · I'm experiencing something similar to this: Should Custom React Hooks Cause Re-Renders of Dependent Components? So, I have something like this: const ComponentA = props =&gt; { const returnedValu Deep Understanding of React’s Inner Workings and Best Practices, From Intermediate to Advanced React Feb 13, 2022 · I am struggling to prevent my whole app getting re-rendered. Sep 19, 2024 · Key Techniques to Optimize Re-Rendering in React 1. Sep 4, 2024 · Understanding when and why a React component re-renders is key to building performant React applications. Aug 8, 2025 · Component Lifecycle: Re-renders in class components are controlled by lifecycle methods, while hooks manage them in functional components. Provider changes? Nov 6, 2020 · Avoiding the perils of re-mounting vs. The guide explains what re-renders are, what a necessary and unnecessary re-render is, what can trigger a React component re-render. You can wrap a React component with memo to prevent an entire subtree from re-rendering. memo , it will only be re-rendered if one of its props changes. I have already read Use context Github issue this thr Oct 23, 2022 · Learn when child components in React re-render and how to structure a React apps with both performance and simplicity in mind. Let's dive into proven strategies to eliminate unnecessary re-renders and boost your React app's performance. With all mid to complex React applications, we will need to implement some type of state management system. Feb 26, 2025 · React. Discover when to use it and how it compares to useMemo and useCallback. But you can prevent components further down to rerender with that. It is a lifecycle method which is available on React class components. Here's the aticle by Josh Comeau that goes more deep into this:more Tech2. Pure components, components that implement shouldComponentUpdate, or components using React. all toasts live in toast provider. Avoiding unnecessary re-renders is essential to keep your React applications fast and efficient. memo and useCallback Let’s first cover the main toolkit under your belt for cutting down the re-renders: memo and useCallback it's not about blocking the re-rendering of the parent component (app in your case) but instead, it helps in performance optimization by avoiding unnecessary re-renders of the child components, if their props haven't changed. memo is a higher-order component (HOC) that helps prevent unnecessary re-renders in functional components by memoizing the result. Not every component under the context provider. Jul 8, 2023 · Learn how to optimize React component rendering by understanding its behavior, improving performance, and avoiding unnecessary re-renders in this comprehensive guide. Global Context Code Oct 23, 2022 · Learn when child components in React re-render and how to structure a React apps with both performance and simplicity in mind. This happens because we are using the global state from react context, and with every update, all components that are using the state will trigger another render to make sure the component is up to date. Jan 20, 2022 · I would like to know how to stop every input/component from re-rendering when an input changes? I would like to render a form with the corresponding data (from my API) like this: { a: 0, b: 0, c: t Feb 22, 2025 · React Performance Guide: Context vs Props, preventing unnecessary rerenders, and proper component optimization with React. Context is great for reading values but not so great when updating values due to the re-rendering. Jul 14, 2019 · This solution is used to prevent a component from rendering in React is called shouldComponentUpdate. Mar 27, 2019 · Which leads to the Provider and all its descendants re-rendering anyways While this is the default behavior, in practice it's common to change this in order to improve performance. memo for Functional Components React. Preventing the re-render of the dropdown is plan A in solving this problem. How can I avoid re-render of other components where there was no change. I have already read Use context Github issue this thr Mar 11, 2022 · The state changes causes the dropdown component to re-render with the initial data passed by App as a prop resetting to having nothing checked. The problem is that whenever I change something, the entire page re-renders and request to the API gets called again (My axios requests in useEffect callback). tsx were triggering the React Hook Form FormProvider, causing other child components to re-render as well. memo, which can be used together to prevent the unnecessary re-rendering of child components within a parent component. Mar 27, 2025 · Note: This article covers optimization techniques for React 18 and React 19 applications, focusing on preventing unnecessary re-renders for improved performance. If not taken seriously, this issue can quickly worsen the performance of your application. The first thing to understand is that React re-renders components recursively by default. this stop in . By default, a React component re-renders whenever there is a change in its state or props. Aug 27, 2025 · I will teach you how to prevent React. Nov 2, 2024 · My Closing Thoughts on the Matter React provides tools and techniques to manage component re-rendering effectively. How React Handles Re-Rendering? React uses a Virtual DOM as an intermediate layer. React handles these operations in three distinct steps: the trigger step, the render step, and the commit step. Let's remove the context from our example and see this behavior in action. Context Usage Skipping re-rendering when props are unchanged React normally re-renders a component whenever its parent re-renders. If the props of a component haven’t changed, React. Use React. It’s always useful to know when unnecessary re-rendering occurs in our code, especially if we have heavy components in our app. First, here the code. Jan 12, 2025 · However, it comes with a common pitfall: unnecessary re-renders of components subscribing to the context. Mar 1, 2019 · React. react-tracked looks like a great solution. Context API is great but we need to be aware of some limitations, this post we will understand one of the limitation which is unnecessary re-rendering of Child Components. memo prevents it from re-rendering. In order to prevent this we can use memo which will skip unnecessary re-renders of that component. Plus, explore the use of gaps over margins and the role of Server Components in Expo. See my extensive post A (Mostly) Complete Guide to React Rendering Behavior for a better understanding of when and why components will get rendered. React Context one of the useful features available in the React JS library. Nov 16, 2024 · I realized that re-renders in MainForm. When a component renders, React will recursively re-render all its children regardless of props or context. By wrapping it in the useCallback, the main state is free to update and trigger re-renders in children using the main context state, but child components that only use the So I know how Hooks work and what's their purpose, but how do we prevent a re-render of a component? For example if I use React Context together with useReducer, how can I tell some functional component to not re-render, where is the componentShouldUpdate here? Jan 21, 2025 · I am trying to prevent as much re-rendering as possible, so I'm using memo. Feb 4, 2025 · Prevent unnecessary re-renders by re-using references passed as props. Dec 31, 2024 · React's virtual DOM and component-based architecture make it incredibly efficient, but without proper optimization, your application can still suffer from performance issues. Depending on how many components are affected I would still try to split the providers. Force Update: You can force a re-render using forceUpdate () in class components, though this is rarely needed. Oct 11, 2018 · A React context Provider will cause its consumers to re-render whenever the value provided changes. memo second argument callback to prevent rendering Or I should have the possibility to return an old instance of the react component in the function body. Since react context works with the provider, all context subscribers are under parent provider. In this blog, we’ll explore how to prevent unnecessary re Jun 4, 2023 · Why re-render only happens when state defined in the Provider wrapper component changes, not when value supplied to Context. To simplify, these steps can be categorized as: initial rendering (mount), re-rendering (update), and component removal (unmount). Re-render Triggers: – State changes Aug 30, 2024 · Understanding Component Re-Rendering with useContext in React When working with React, state management is a crucial aspect of building responsive and dynamic applications. I want us to understand how it works and also how you can optimize if needed. It is a misnomer, and I'm here to disprove it. By understanding and implementing these practices, you can avoid the problem and keep your rendering process running smoothly. Mar 19, 2019 · I should have somehow access to the context in React. However, there are common cases where components do not update as expected leading to stale UI and bugs that are hard to uncover. This is causes people to avoid using context, and jumping straight to tools like Redux or Zustand. With solutions like the built-in React Context API … May 9, 2025 · I commonly see people having the belief that react context is not appropriate for managing state, because every time its state changes, it'll cause everything under the React provider to re-render. To address this issue, React provides two hooks, useCallbackand React. Jan 5, 2022 · Like any other utility, you need to know how to use React Context to get best of out it to prevent unnecessary re-renders that may occur. Jun 15, 2020 · Using React. memo allows you to memoize a component which can help preventing unecessary re-renders. Essentially whenever a state value in the context changes, the entire components that are wrapped between the provider re-rend Currently using context to store an id for one specific table cell. Oct 27, 2025 · In this article, we’ll explore how and why React re-renders happen, and more importantly, how to prevent them with smarter architecture choices — from context splitting to selector-based Jul 8, 2023 · In this article, we will explore three React Hooks and how they prevent unnecessary renderings in React. Sep 19, 2024 · When writing React components, we always strive to keep optimization in mind. The Problem: Unnecessary Re-renders When using the Context API, you typically create a single context and pass down the state and dispatch function in a new object as the value of that context. Only the components THAT USE THE CONTEXT re-render. memo will cause the rerendering to stop before going through the entire tree. React's component-based architecture provides a powerful model for building user interfaces, but with that power comes the responsibility of ensuring your applications render efficiently. Until then, Happy Sep 25, 2021 · How did I re-render: Sharing State through React-Context Like any other utility, you need to know how to use React Context to get the best of out it to prevent unnecessary… Nov 21, 2023 · When a component in React consumes values from the Context API and the value of the context changes, that component re-renders. In addition to being specific, you can also use memoization to prevent running the useEffect () hook when it's not necessary. The refactor was because of a common problem in React projects: Pass a lot of props to the child components, then you have to pass them to the child of them, and so. memo is usually the best option but probably won't help much here, as it will still rerender since it's basically a state change. This works: export default function About() { This causes infinite re-renders on context update: export default async function About() { Both are maked as "use client"; Expected After every re-render with changed dependencies, React will first run the cleanup function (if you provided it) with the old values, and then run your setup function with the new values. However, once I relocated the FormProvider, it stopped the unnecessary re-renders, including in the components where I use useFormContext. Since updating context means setting state in a parent component, you actually end up rendering all components by default anyway. Jun 12, 2018 · The updates to context values doesn't trigger re-render for all the children of the provider, rather only components that are rendered from within the Consumer, so in your case although number component contains the Consumer, Number component isn't re-rendered, rather just the render function within the Consumer and hence the value changes on Understand when React triggers re-renders, how to optimize performance, and prevent unnecessary updates for a faster UI experience. It is possible to download these free files and install them on your server, so you can test how the site works. The problem is you are memoizing the piece where you use the context. My question is how can I make my component never re-render even if props change, and without using a class. In most cases we use child components by their name. Jun 23, 2024 · React Context and Re-renders In this post, we'll dive into how re-renders happen in the situation of React Context. Trigger step The trigger May 2, 2023 · This can help improve the performance of your application and prevent unnecessary re-rendering. By using memoization, optimizing context usage, and grouping state, you can enhance the performance of your React applications significantly. Feb 12, 2021 · Only re-rendering React components when necessary can make your app faster. However, in many cases, this behavior can lead to unnecessary renders, particularly when the child component’s output does not depend on the updated state. Sep 26, 2021 · I know this is well known issue and there are so many articles and questions and answers. Jan 13, 2020 · Why does this happen? Every time React detects a change to something inside its context, it triggers a re-render on all of the context subscribers so that they can receive, the new changes. In this article,I'll explore why this happens, evaluate common solutions, and ultimately present a scalable approach using useReducer to solve this problem effectively. How can I prevent this behavior like in Redux, where the component will re-render if the state being used is changed? Find out when and how to use React force rerender and manage renderstate for smoother and more seamless user experiences. useEffect(() => { // do something }, [someState]) Remember, non-primitives can't be directly compared by their value. Feb 16, 2025 · This is the core principal of Context API, when a context value changed all components re-render. May 2, 2023 · This can help improve the performance of your application and prevent unnecessary re-rendering. Sep 23, 2021 · Improve your React app's performance by eliminating unnecessary re-renders with React Tracked, a library for state usage tracking. In this article we will have a look over Context, creating a basic example of Cart being stored in our global Aug 22, 2023 · Use React. When one todo changes, an action is dispatched, causing the state to update. Jun 11, 2025 · A clear, no-fluff guide to understanding how React decides what to re-render — and how you can optimize it. memo prevents unnecessary re-renders, improving performance. This solution is suitable for functional components with heavy computation or when you know the props won't change frequently. The problem: Updating that context value causes Component A to re-render (which makes sense, I changed a parent), and because of this, all of the text edits are reverted as everything remounts using the starting value of userTemplates (remember, I'm mapping over this array to create the list of editable divs). 2 I'm creating a simple React todo app using context and useReducer, and I'm unsure how to prevent every single todo item from re-rendering when one of the changes. Sep 24, 2023 · 0 I have been trying to optimise the my react code, my goal is to make sure existing toast components don't re render when new ones are added. Today, I want … Apr 16, 2022 · Meaning when we try to render the page the function gets called and therefore causes another render. It's only when you start React will re-render every child that subscribes to context when any of the state in that context is changed. However Nov 16, 2024 · I realized that re-renders in MainForm. ozkogh tfihwe jmb biegn uvanalf kldw lxpnw zhlbr aifkns sdx ffhepgnxw ilpsnw wkj zpgzrjn hegg