TypeScript icon, indicating that this package has built-in type declarations

    1.8.1 • Public • Published

    use-deep-compare-effect 🐋

    It's React's useEffect hook, except using deep comparison on the inputs, not reference equality

    Build Status Code Coverage version downloads MIT License All Contributors PRs Welcome Code of Conduct

    WARNING: Please only use this if you really can't find a way to use React.useEffect. There's often a better way to do what you're trying to do than a deep comparison.

    The Problem

    React's built-in useEffect hook has a second argument called the "dependencies array" and it allows you to optimize when React will call your effect callback. React will do a comparison between each of the values (via to determine whether your effect callback should be called.

    The problem is that if you need to provide an object for one of those dependencies and that object is new every render, then even if none of the properties changed, your effect will get called anyway.

    Table of Contents


    This module is distributed via npm which is bundled with node and should be installed as one of your project's dependencies:

    npm install --save use-deep-compare-effect


    You use it in place of React.useEffect.

    NOTE: Only use this if your values are objects or arrays that contain objects. Otherwise, you should just use React.useEffect. In case of "polymorphic" values (eg: sometimes object, sometimes a boolean), use useDeepCompareEffectNoCheck, but do it at your own risk, as maybe there can be better approaches to the problem.

    NOTE: Be careful when your dependency is an object which contains function. If that function is defined on the object during a render, then it's changed and the effect callback will be called every render. Issue has more context.


    import React from 'react'
    import ReactDOM from 'react-dom'
    import useDeepCompareEffect from 'use-deep-compare-effect'
    function Query({query, variables}) {
      // some code...
        () => {
          // make an HTTP request or whatever with the query and variables
          // optionally return a cleanup function if necessary
        // query is a string, but variables is an object. With the way Query is used
        // in the example above, `variables` will be a new object every render.
        // useDeepCompareEffect will do a deep comparison and your callback is only
        // run when the variables object actually has changes.
        [query, variables],
      return <div>{/* awesome UI here */}</div>

    Other Solutions



    Looking to contribute? Look for the Good First Issue label.

    🐛 Bugs

    Please file an issue for bugs, missing documentation, or unexpected behavior.

    See Bugs

    💡 Feature Requests

    Please file an issue to suggest new features. Vote on feature requests by adding a 👍. This helps maintainers prioritize what to work on.

    See Feature Requests


    Thanks goes to these people (emoji key):

    Kent C. Dodds

    💻 📖 🚇 ⚠️

    Edygar de Lima Oliveira

    💻 ⚠️

    Justin Dorfman


    Anton Halim


    Michaël De Boey


    Tobias Büschel


    Peter Hozák


    Ricardo Busquet


    Dave Johansen


    Sam Knutson


    Albert Lucianto

    🐛 💻 ⚠️

    Jasper Chang




    This project follows the all-contributors specification. Contributions of any kind welcome!






    npm i use-deep-compare-effect

    DownloadsWeekly Downloads






    Unpacked Size

    44.2 kB

    Total Files


    Last publish


    • kentcdodds