Benchmark: React.memo vs no React.memo

HTML Preparation code:

<div id="root"></div>
<script src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.15/lodash.min.js"></script>

Script Preparation code:

var Memo = (props) => {
  return React.createElement("div", { className: props.css });
};

var NoMemo = React.memo((props) => {
  return React.createElement("div", { className: props.css });
});

var list = new Array(1000).fill({css: Math.random()});

Tests:

React.memo
list.forEach((p) => { ReactDOM.render(React.createElement(Memo, p, null), root); });
No React.memo
list.forEach((p) => { ReactDOM.render(React.createElement(NoMemo, p, null), root); });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
React.memo
No React.memo

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 10 months ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser/OS: Chrome 137 on Windows

View result in a separate tab

Test name	Executions per second
React.memo	56.6 Ops/sec
No React.memo	70.9 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

LLMs can make mistakes. Check important info.

Let's break down the benchmark and explain what's being tested.

**Benchmark Definition**

The benchmark is comparing two approaches: using `React.memo` and not using it, when rendering a list of components in React.

**Script Preparation Code**

The script preparation code defines two functions:

1. `Memo`: a function that takes props as an argument and returns a `<div>` element with a class name set to the prop's `css` value.
2. `NoMemo`: a function that is similar to `Memo`, but without the use of `React.memo`. This function will not perform any optimizations when rendering the component.

**Html Preparation Code**

The HTML preparation code sets up a React environment by including the necessary libraries:

1. React
2. React DOM
3. Lodash (a utility library)

**Individual Test Cases**

There are two test cases:

1. **React.memo**: The script defines a `list` array with 1000 elements, each with a random `css` value. Then, it uses the `forEach` method to iterate over the list and render each element using the `Memo` function. The resulting React component tree is rendered on a DOM node (`root`).
2. **No React.memo**: This test case is similar to the first one, but without the use of `React.memo`. Instead, it uses the `NoMemo` function to define the rendering logic.

**Library and Purpose**

In both cases, Lodash is used as a utility library. Its purpose in this benchmark is likely to provide a way to generate random values for testing purposes.

**Special JS Features or Syntax**

There are no special JavaScript features or syntaxes being tested in this benchmark. The focus is on comparing the performance of two approaches: using `React.memo` and not using it.

**Pros and Cons**

**Using React.memo**:

Pros:

* Optimizes the rendering of components by only re-rendering components that have changed.
* Can improve performance by reducing the number of unnecessary re-renders.

Cons:

* May require additional setup and configuration.
* Can make debugging more challenging due to the optimized rendering behavior.

**Not Using React.memo**:

Pros:

* Simplifies code and debugging.
* Does not require additional setup or configuration.

Cons:

* May result in slower performance due to unnecessary re-renders.
* Can lead to increased memory usage and garbage collection.

**Other Alternatives**

If you're interested in exploring alternative approaches, here are a few options:

1. **React Preact**: A faster and more lightweight version of React that's optimized for server-side rendering and performance.
2. **Enzyme**: A testing library for React that provides tools for writing unit tests and integrating with Jest or Mocha.
3. **Redux**: A state management library that provides a way to manage global state in applications.

These alternatives can help you explore different approaches to building and testing React applications, but may not provide the same level of optimization as `React.memo`.

Related benchmarks:

React.memo vs no React.memo (version: 0)

Comparing performance of: React.memo vs No React.memo

Created: 3 years ago by: Guest

Jump to the latest result

React.memo

No React.memo

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):