Latest Ext JS 7.8 is now available. Learn more

7 Tips for Optimizing Performance in JavaScript Grids

February 28, 2024 886 Views

Advanced data grid built using the Ext JS framework

A JavaScript data grid is a UI element that enables developers to efficiently present data in a tabular format. These grids essentially allow us to organize large datasets and present them in an easy-to-understand, structured format. Moreover, data grids make it easier to compare data and highlight trends and patterns. Thus, JavaScript grids have become an essential part of many modern web apps, especially data-intensive enterprise-grade apps. However, creating JS grids from scratch can be challenging and time-consuming. One common challenge that developers often face while building JavaScript grids is optimizing the grid’s performance. This is especially true for grids presenting very large and complex datasets with advanced features like filtering, sorting, grouping, etc.

Unoptimized grids directly affect the load time, responsiveness, and interactivity of the web app, which significantly impacts the user experience. Thus, optimizing data grid performance is of paramount importance. Fortunately, there are various effective ways to enhance the performance of JavaScript grids and make them more efficient. For instance, JS frameworks like Ext JS JavaScript framework or grid libraries like ag-Grid and Tabulator allow us to integrate highly interactive and optimized JS grids into our web applications.

This article will explore seven effective ways to optimize the performance of JavaScript grids.

Choose the Right Grid Library/Framework

Creating a high-performance grid that can handle large volumes of data from scratch can be quite challenging. That’s why most developers today use a specialized JavaScript library or a JS framework for creating grids.

A JavaScript grid library is essentially software that provides pre-written code or pre-built functionality for creating data grids for web apps. These libraries enable developers to integrate customizable and high-performance grids into their apps and offer a range of features, such as filtering, sorting, grouping, etc. Thus, these libraries simplify the process of building robust grids with advanced features. While several JavaScript grid libraries are available today, not all libraries are made equal.

Here are the key factors to consider when choosing a JavaScript framework or library for creating a data grid:

  • Evaluate the ease of integration of the library or framework into your web app.
  • Compare the framework’s features against your project requirements to ensure it provides the necessary features and functionality. For instance, you’ll need pagination and sorting for datasets containing large amounts of information.
  • Assess the framework’s ability to handle large datasets and complex grid features.
  • Assess the level of grid customization the framework offers. This includes options for customizing grid appearance/styling, layout, behavior, and functionality to meet your project’s unique design and functionality requirements.
  • Evaluate the documentation and developer community of the framework/library. Choosing a framework with extensive documentation and an active developer community will make it easier to implement the grid and solve any issues you may encounter while implementing it.

Some of the most popular JavaScript libraries for JS grids include:

AG Grid JavaScript Library

JS frameworks - AG grid library

AG Grid allows you to create high-performance data grids that can handle large datasets efficiently. The library supports plain JavaScript as well as popular JavaScript frameworks, such as React, Vue, and Angular.

AG Grid offers a wide range of features, such as:

  • Sorting
  • Filtering
  • Grouping
  • Row selection
  • Virtual scrolling
  • Chart integration
  • Row and range selection
  • Cell Rendering
  • In-table editing


SlickGrid is a lightweight open-source JS grid library focusing on customization and performance. The library offers various advanced features, such as:

  • Column resizing
  • Sorting
  • Filtering
  • Customizable cell editors
  • Virtual scrolling
  • Column reordering
  • Inline editing

Ext JS JavaScript framework


JS frameworks - Sencha Ext JS - the best JavaScript framework for creating interactive user interfaces

Ext JS isn’t a JavaScript grid library but a full-fledged feature-rich JavaScript framework for building high-performance enterprise-grade web and mobile applications. The robust framework is cross-browser and cross-platform compatible, has extensive documentation, and excellent community support. The framework is widely recognized for highly customizable and fully tested pre-built UI web components, accelerating the web development process.

Essentially, Ext JS offers over 140 pre-built UI components, including a blazing-fast JS grid. The efficient grid can handle thousands of records/large volumes of data without compromising performance.

Blazing fast JS grid by Ext JS

Prominent features of Ext JS data grids include:

  • Rich data visualization (developers can add various types of elements to grid cells, such as text, icons, images, graphs, etc.)
  • Advanced sorting and filtering
  • Column recording and resizing
  • Pagination
  • Infinite scrolling
  • Inline cell editing and batch updating
  • Grouping
  • Summary rows and row expansion
  • Drag-and-drop interaction (users can reorder or rearrange rows and columns through drag-and-drop)
  • Customization (developers can customize the appearance and styling of the grid to match their app’s design requirements)
  • Seamless integration Ext Data Stores to fetch grid data
  • Two-way data binding

Data Pagination and Virtualization

Pagination means splitting a grid with large datasets into various smaller and more manageable chunks or pages. With pagination, developers can customize the number of items per page and the navigation controls. It is a very useful technique for optimizing grid performance, especially for large datasets.

Pagination basically reduces the amount of data loaded and presented on the client side at a given time. This leads to faster initial rendering and load times and reduced memory usage, resulting in smoother and more responsive user interactions and enhanced user experience. Moreover, pagination enables users to interact with the grid more efficiently and navigate through the data more easily.

Pagination also makes the grid more scalable, allowing us to present thousands of records without affecting the app’s speed, responsiveness, and performance. This scalability is crucial for apps dealing with rapidly growing data volumes or serving many concurrent users.

Virtualization is another helpful technique for handling large datasets efficiently. Instead of loading the entire dataset into memory and rendering it all at once, virtualization only renders the visible portion of the data. The rest of the data is loaded dynamically as the user scrolls through the dataset. Common virtualization techniques for grids include row virtualization and column virtualization.

Banner: C-Level Guide for Enterprise Application Development

Use Efficient Data Binding

Data binding in a JavaScript grid allows us to connect the grid’s UI (user interface) and the underlying data source. This way, the grid can efficiently display the changes made to the data source. Thus, data binding ensures that the grid synchronizes with the data source efficiently and always displays up-to-date information.

Two main types of data binding commonly used in JS grids include:

One-Way Data Binding

In one-way data binding, the grid automatically displays the changes made to the data source. However, the changes made within the grid do not affect or modify the underlying data source. This means that the grid is read-only, and if we actually want to update or modify the grid data, it must be done through the data source.

Two-Way Data Binding

In two-way data binding, changes made to the data source are automatically reflected in the grid, and the updates made to the grid are reflected in the data source. Two-way data binding provides a more interactive and seamless user experience, as changes made in one place are automatically reflected in the other.

If you’re looking to implement two-way data binding in grids, choosing a library or framework that supports two-way data binding is essential. For example, Ext JS supports two-way data binding to create web applications that efficiently reflect the changes made to the data and vice versa.

Here is an example of two-way data binding with cell editing using Ext JS:

Ext.define('MyApp.view.MyEditableGrid', {
    extend: 'Ext.grid.Panel',
    xtype: 'myeditablegrid',

    title: 'Editable Grid',
    store: {
        type: 'myeditabledatastore' // Assume 'myeditabledatastore' is defined elsewhere
    columns: [
        { text: 'ID', dataIndex: 'id', editor: 'textfield' },
        { text: 'Name', dataIndex: 'name', editor: 'textfield' },
        { text: 'Age', dataIndex: 'age', editor: 'numberfield' }
    plugins: {
        ptype: 'cellediting',
        clicksToEdit: 1

    // Other grid configuration options...

Also Read: Next-Gen UI Components: Elevating User Interfaces with JavaScript in 2024

Optimize Rendering with Debouncing and Throttling

Developers often face rendering issues in JavaScript grids, especially when dealing with frequent updates of large amounts of data. These issues can significantly affect the performance and responsiveness of the user interface, impacting the user experience. Common rendering issues in JS grids include excessive or inefficient DOM manipulations, slow rendering times, unresponsive user interfaces, and increased CPU utilization.

Fortunately, debouncing and throttling techniques can help optimize the grid’s rendering performance and overcome these issues.

Debouncing basically delays the execution of a time-consuming task or function. It ensures that the function is only called once after multiple rapid invocations. Thus reducing the number of function calls and minimizing unnecessary rendering.

Throttling limits the rate or frequency at which a function can be executed. It ensures that the function is called at regular intervals, preventing multiple rapid executions.

Minimize DOM Manipulation

As discussed in the above section, frequent DOM (Document Object Model) manipulations in JS grids cause rendering issues, leading to UI freezes, increased memory consumption, and performance degradation, especially in grids with large datasets.

In addition to debouncing and throttling, here are some effective ways to minimize DOM manipulations:

  • Batch multiple DOM updates together to prevent unnecessary reflows and re-rendering. For example, using the Ext JS framework, you can leverage the ‘batchLayout’ method to combine multiple updates into one operation for efficient code execution.
  • Utilize a virtual DOM/ virtual document object model, a helpful feature offered by the best JavaScript frameworks like React and Vue. Virtual DOM helps minimize the number of actual DOM manipulations.
  • Update only the necessary elements in the DOM instead of re-rendering the entire grid.

If you’re using Ext JS, you can also leverage the buffered store to improve the rendering performance of grids with large datasets. Buffered rendering essentially renders only the visible portion of the grid’s content and dynamically loads additional rows as the user scrolls.

Here is an example code for using the Ext JS buffered store:

Ext.create('Ext.grid.Panel', {
    title: 'My Grid',
    store: {
        type: 'bufferedstore', // Use a buffered store for large datasets
        pageSize: 50, // Set the page size for optimal rendering
        proxy: {
            type: 'ajax',
            url: 'data.json' // URL to fetch data from the server
    columns: [
        { text: 'ID', dataIndex: 'id' },
        { text: 'Name', dataIndex: 'name' },
        { text: 'Age', dataIndex: 'age' }
    height: 400,
    width: 600

Here is an example code for updating Ext JS store data efficiently:

// Assume 'myStore' is an instance of

// Batched updates using suspendEvents/resumeEvents
myStore.loadData(newData); // Load new data into the store
myStore.fireEvent('refresh'); // Manually trigger store refresh

// Alternatively, use loadRawData for non-paginated stores
myStore.loadRawData(newData, true); // Pass true to append new data

Implement Client-Side Sorting and Filtering

Client-side sorting and filtering in JavaScript grids means performing sorting and filtering operations directly within the client’s browser without server-side processing. This allows developers to optimize the app’s performance and enhance user experience by reducing server load and improving response times and interactivity.

Ext JS provides robust support for client-side sorting and filtering in its grid components, allowing developers to implement these features seamlessly.

Here is an example JavaScript code for client-side sorting in Ext JS grids:

Ext.create('Ext.grid.Panel', {
    title: 'My Grid',
    store: {
        type: 'gridstore', // Define store configuration
        // Other store configuration options...
    columns: [
        { text: 'ID', dataIndex: 'id', sortable: true }, // Enable sorting for ID column
        { text: 'Name', dataIndex: 'name', sortable: true }, // Enable sorting for Name column
        { text: 'Age', dataIndex: 'age', sortable: true } // Enable sorting for Age column
    // Other grid configuration options...

Optimize Event Handling

JS frameworks - A Person coding on Macbook Pro

Event handling in JavaScript grids allows the grid to respond to user actions to deliver a more responsive and engaging user experience. However, event handling in JavaScript grids can be challenging due to the complexity of the data these grids deal with. Common event handling challenges include:

  • In grids with large datasets, binding event listeners to individual elements can result in excessive event bindings. This leads to increased memory usage, affecting the performance.
  • In nested grids, event propagation is challenging, leading to unintended event triggering or bubbling.
  • Handling multiple events simultaneously, such as row selections, cell clicks, and keyboard navigation, can result in event collisions and conflicts.

Here are some ways to optimize event handling:

  • Utilize event delegation to bind event listeners to parent elements instead of individual grid elements. This will help reduce the number of event listeners and improve performance, especially in grids with dynamic content.
  • Bind event listeners to elements that require them instead of binding them to the entire grid.
  • Implement throttling and debouncing techniques for events that may trigger frequent updates, such as scroll or resize events.
  • Implement virtual scrolling in grids to handle scroll events efficiently.


JavaScript grids often deal with large volumes of data. Thus, if they aren’t optimized properly, they can cause performance issues like slow rending, unresponsive grid or UI, slow loading times, and increased memory usage. Here are some effective tips (that we’ve discussed in this article) to overcome these issues:

  • Choose the right grid library framework
  • Leverage data pagination and virtualization techniques
  • Use efficient data binding
  • Optimize rendering with debouncing and throttling
  • Minimize DOM manipulation
  • Implement client-side sorting and filtering
  • Optimize event handling

Frequently Asked Question

Why is performance optimization crucial for JavaScript grids?

Optimizing performance in JavaScript grids allows us to create highly interactive, responsive, and fast grids.

How do I choose the right JavaScript grid library for my project?

While there are different JavaScript frameworks and grid libraries, choosing the right library or framework for your app is essential. Consider factors like ease of integration, grid features, customization options, documentation and community support.

How can developers optimize event handling in JavaScript grids?

Developers can utilize techniques like event delegation, event binding, debouncing, and throttling to optimize event handling in JavaScript grids.

What are the most popular JavaScript frameworks?

Ext JS and React are the most popular JavaScript frameworks. Ext JS is a robust framework for enterprise-grade app development. React is an open-source JavaScript framework known for its component-based architecture and virtual DOM.

Sencha CTA Banner: Try Sencha Ext JS