JavaScript Data GridRow virtualization

Render thousands of rows without freezing the browser, using row virtualization.

Overview
Configuring row virtualization
Known limitations
Related articles
- Related guides
- Related API reference

Overview

Virtualization allows Handsontable to process hundreds of thousands of records without causing the browser to hang. This feature draws only the visible part of the grid, displaying the minimum items physically rendered in the DOM. The elements outside the viewport are rendered when you scroll across the grid. Depending on your configuration, there might be a small offset of columns or rows rendered outside the viewport to make the scrolling performance smoother.

This feature is enabled by default and can be turned off by setting the renderAllRows option to true.

Configuring row virtualization

You can experiment with the viewportRowRenderingOffset configuration option, which determines the number of rows displayed outside the visible viewport. If the number passed to that option is greater than the total columns in your data set, then the virtualization will be practically turned off.

To make the grid scrollable, set the constant width and height to the same as the container holding Handsontable and set the overflow property to hidden in the container's stylesheet. If the table contains enough rows or columns, it will be scrollable.

The scrolling performance depends mainly on four factors:

Number of cells - number of rows multiplied by the number of columns
Amount and complexity of custom renderers in cells
Number of options enabled in the configuration
Performance of your setup - physical machine and a browser

The example below presents a data grid displaying 1 million cells (1000 rows x 1000 columns):

{
    "name": "handsontable",
    "version": "1.0.0",
    "description": "",
    "dependencies": {
      "hyperformula": "^2.4.0",
      "handsontable": "15.0"
    }
  }

<!DOCTYPE html>
  <html>
    <head>
      <meta charset="utf-8" />
      <meta name="viewport" content="width=device-width, initial-scale=1.0" />
      <title>Handsontable</title>
    </head>
  
    <body>
      <div id="example1" class="hot ht-theme-main-dark-auto "></div>
    </body>
  </html>

import './styles.css'
import Handsontable from 'handsontable';
import 'handsontable/styles/handsontable.css';
import 'handsontable/styles/ht-theme-main.css';

// generate an array of arrays with dummy data
const data = new Array(1000) // number of rows
  .fill(null)
  .map((_, row) =>
    new Array(1000) // number of columns
      .fill(null)
      .map((_v, column) => `${row}, ${column}`)
  );

const container = document.querySelector('#example1');

new Handsontable(container, {
  data,
  colWidths: 100,
  width: '100%',
  height: 320,
  rowHeaders: true,
  colHeaders: true,
  autoWrapRow: true,
  autoWrapCol: true,
  licenseKey: 'non-commercial-and-evaluation',
});

import Handsontable from 'handsontable';
import 'handsontable/styles/handsontable.css';
import 'handsontable/styles/ht-theme-main.css';

// generate an array of arrays with dummy data
const data = new Array(1000) // number of rows
  .fill(null)
  .map((_, row) =>
    new Array(1000) // number of columns
      .fill(null)
      .map((_v, column) => `${row}, ${column}`)
  );

const container = document.querySelector('#example1');

new Handsontable(container, {
  data,
  colWidths: 100,
  width: '100%',
  height: 320,
  rowHeaders: true,
  colHeaders: true,
  autoWrapRow: true,
  autoWrapCol: true,
  licenseKey: 'non-commercial-and-evaluation',
});

<script src="https://cdn.jsdelivr.net/npm/handsontable@15.0/dist/handsontable.full.min.js"></script>
<link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable@15.0/styles/handsontable.min.css" /> 
<link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable@15.0/styles/ht-theme-main.css" /> 
<link type="text/css" rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable@15.0/styles/ht-theme-horizon.css" /> 
<script src="https://handsontable.com/docs/scripts/fixer.js"></script>

<div id="example1" class="hot ht-theme-main-dark-auto "></div>

Known limitations

Using row virtualization has the following side effects:

The browser's native search will work only for the visible part of the grid.
Screen readers may announce the wrong total number of rows. Read more in the Accessibility guide.

Configuration options:
- renderAllRows
- viewportRowRenderingOffset

JavaScript Data GridRow virtualization

Overview

Configuring row virtualization

Known limitations

Related articles

Related guides

Related API reference