Converting Excel worksheets into image formats like PNG or JPEG can be useful for sharing spreadsheet data in presentations, reports, or other documents. Unlike Excel files, image formats ensure that the formatting and structure remain consistent, regardless of the viewer’s software or platform. In this article, we will demonstrate how to convert Excel to images in React using Spire.XLS for JavaScript.
- Convert an Excel Worksheet to an Image
- Convert an Excel Worksheet to an Image without White Margins
- Convert a Specific Cell Range to an Image
Install Spire.XLS for JavaScript
To get started with converting Excel to images in a React application, you can either download Spire.XLS for JavaScript from our website or install it via npm with the following command:
npm i spire.office
The downloaded product package has been integrated Spire.Doc for JavaScript，Spire.XLS for JavaScript，Spire.PDF for JavaScript，Spire.Presentation for JavaScript. To use the functionality of Spire.XLS for JavaScript, you need to copy the corresponding files (spire.xls.js, Spire.Xls.Wasm.zip, spire.common.js, Spire.Common.Wasm.zip, and _framework) to the project's "public" folder. At the same time, in order to ensure text rendering, the related font files can be added with custom paths. In the following example, the font addition path is: public\static\font.
For more details, refer to the documentation: How to Integrate Spire.XLS for JavaScript in a React Project.
Convert an Excel Worksheet to an Image with JavaScript in React
Spire.XLS for JavaScript allows you to convert a worksheet into an image using the Worksheet.ToImage() function. Once the conversion is complete, you can save the image in formats such as PNG, JPG, or BMP with the Image.Save() function. The key steps are as follows.
- Load the font file to ensure correct text rendering.
- Create a Workbook object using the new wasmModule.Workbook() function.
- Load the Excel file using the Workbook.LoadFromFile() function.
- Get a specific worksheet using the Workbook.Worksheets.get(index) function.
- Convert the worksheet to an image using the Worksheet.ToImage() function.
- Save the image to a PNG file using the Image.Save() function (you can also save the image in other image formats such as JPG and BMP).
Code example:
- JavaScript
import React, { useState, useEffect } from 'react';
function App() {
const [wasmModule, setWasmModule] = useState(null);
// Load Spire.XLS
useEffect(() => {
(async () => {
try {
const publicUrl = process.env.PUBLIC_URL || '';
const spireModule = await import(/* webpackIgnore: true */ `${publicUrl}/spire.xls.js`);
const rawModule = spireModule.default || spireModule;
window.wasmModule = typeof rawModule === 'function'
? await rawModule({ locateFile: p => p.endsWith('.wasm') ? `${publicUrl}/${p}` : p })
: rawModule;
setWasmModule(window.wasmModule);
} catch (error) {
console.error('Failed to load spire.xls.js WASM module:', error);
}
})();
}, []);
// Function to convert an Excel Worksheet to an Image
const ExcelToImage = async () => {
const wasmModule = window.wasmModule.spirexls;
if (wasmModule) {
// Load font into Virtual File System (VFS)
await window.spire.FetchFileToVFS('Arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/static/font/`);
// Load input file into Virtual File System (VFS)
const inputFileName = 'ToPDF.xlsx';
await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/static/data/`);
// Create a new workbook
const workbook = new wasmModule.Workbook();
// Load existing Excel document
workbook.LoadFromFile({ fileName: inputFileName });
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Convert the sheet to an image
let image = sheet.ToImage(sheet.FirstRow, sheet.FirstColumn, sheet.LastRow, sheet.LastColumn);
// Specify the output image file path
const outputFileName = 'SheetToImage.png';
//Save the image
image.Save(outputFileName);
// Read the saved file and convert to Blob object
const modifiedFileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'image/png' });
// Create a URL for the Blob and initiate download
const url = URL.createObjectURL(modifiedFile);
const a = document.createElement('a');
a.href = url;
a.download = outputFileName;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);
// Clean up resources used by the workbook
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Convert an Excel Worksheet to Image Using JavaScript in React</h1>
<button onClick={ExcelToImage} disabled={!wasmModule}>
Convert
</button>
Run the code to launch the React app at localhost:3000. Once it's running, click on the "Convert" button to convert the specified Excel worksheet to image:
The below screenshot shows the input Excel worksheet and the converted image:
Convert an Excel Worksheet to an Image without White Margins with JavaScript in React
When converting an Excel worksheet to an image, the default output may include unnecessary white margins that can affect the appearance and usability of the image. If you want to remove these white margins, you can set the left, right, top, and bottom margins of the worksheet to zero. The key steps are as follows.
- Load the font file to ensure correct text rendering.
- Create a Workbook object using the new wasmModule.Workbook() function.
- Load the Excel file using the Workbook.LoadFromFile() function.
- Get a specific worksheet using the Workbook.Worksheets.get(index) function.
- Remove all margins from the worksheet by setting its left, right, top, and bottom margin values to zero using the Worksheet.PageSetup.TopMargin, Worksheet.PageSetup.BottomMargin, Worksheet.PageSetup.LeftMargin, and Worksheet.PageSetup.RightMargin properties.
- Convert the worksheet to an image using the Worksheet.ToImage() function.
- Save the image to a PNG file using the Image.Save() function.
Code example:
- JavaScript
import React, { useState, useEffect } from 'react';
function App() {
const [wasmModule, setWasmModule] = useState(null);
// Load Spire.XLS
useEffect(() => {
(async () => {
try {
const publicUrl = process.env.PUBLIC_URL || '';
const spireModule = await import(/* webpackIgnore: true */ `${publicUrl}/spire.xls.js`);
const rawModule = spireModule.default || spireModule;
window.wasmModule = typeof rawModule === 'function'
? await rawModule({ locateFile: p => p.endsWith('.wasm') ? `${publicUrl}/${p}` : p })
: rawModule;
setWasmModule(window.wasmModule);
} catch (error) {
console.error('Failed to load spire.xls.js WASM module:', error);
}
})();
}, []);
// Function to convert an Excel Worksheet to an Image
const ExcelToImage = async () => {
const wasmModule = window.wasmModule.spirexls;
if (wasmModule) {
// Load font into Virtual File System (VFS)
await window.spire.FetchFileToVFS('Arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/static/font/`);
// Load input file into Virtual File System (VFS)
const inputFileName = 'ToPDF.xlsx';
await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/static/data/`);
// Create a new workbook
const workbook = new wasmModule.Workbook();
// Load existing Excel document
workbook.LoadFromFile({ fileName: inputFileName });
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Set all margins of the worksheet to zero
sheet.PageSetup.LeftMargin = 0;
sheet.PageSetup.BottomMargin = 0;
sheet.PageSetup.TopMargin = 0;
sheet.PageSetup.RightMargin = 0;
// Convert the sheet to image
let image = sheet.ToImage(sheet.FirstRow, sheet.FirstColumn, sheet.LastRow, sheet.LastColumn);
// Specify the output image file path
const outputFileName = 'SheetToImageWithoutMargins.png';
//Save the image
image.Save(outputFileName);
// Read the saved file and convert to Blob object
const modifiedFileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'image/png' });
// Create a URL for the Blob and initiate download
const url = URL.createObjectURL(modifiedFile);
const a = document.createElement('a');
a.href = url;
a.download = outputFileName;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);
// Clean up resources used by the workbook
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Convert an Excel Worksheet to Image Using JavaScript in React</h1>
<button onClick={ExcelToImage} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Convert a Specific Cell Range to an Image with JavaScript in React
Converting a specific cell range to an image lets you highlight essential data, making it easy to share or embed without including unnecessary information. Spire.XLS for JavaScript enables you to convert a specific cell range from a worksheet into an image by providing the starting and ending row and column indices as parameters to the Worksheet.ToImage() function. The key steps are as follows.
- Load the font file to ensure correct text rendering.
- Create a Workbook object using the new wasmModule.Workbook() function.
- Load the Excel file using the Workbook.LoadFromFile() function.
- Get a specific worksheet using the Workbook.Worksheets.get(index) function.
- Convert a specific cell range of the worksheet to an image using the Worksheet.ToImage() function and pass the index of the start row, start column, end row, and end column of the cell range to the method as parameters.
- Save the image to a PNG file using the Image.Save() function
Code example:
- JavaScript
import React, { useState, useEffect } from 'react';
function App() {
const [wasmModule, setWasmModule] = useState(null);
// Load Spire.XLS
useEffect(() => {
(async () => {
try {
const publicUrl = process.env.PUBLIC_URL || '';
const spireModule = await import(/* webpackIgnore: true */ `${publicUrl}/spire.xls.js`);
const rawModule = spireModule.default || spireModule;
window.wasmModule = typeof rawModule === 'function'
? await rawModule({ locateFile: p => p.endsWith('.wasm') ? `${publicUrl}/${p}` : p })
: rawModule;
setWasmModule(window.wasmModule);
} catch (error) {
console.error('Failed to load spire.xls.js WASM module:', error);
}
})();
}, []);
// Function to convert an Excel Worksheet to an Image
const ExcelToImage = async () => {
const wasmModule = window.wasmModule.spirexls;
if (wasmModule) {
// Load font into Virtual File System (VFS)
await window.spire.FetchFileToVFS('Arial.ttf', '/Library/Fonts/', `${process.env.PUBLIC_URL}/static/font/`);
// Load input file into Virtual File System (VFS)
const inputFileName = 'ToPDF.xlsx';
await window.spire.FetchFileToVFS(inputFileName, '', `${process.env.PUBLIC_URL}/static/data/`);
// Create a new workbook
const workbook = new wasmModule.Workbook();
// Load existing Excel document
workbook.LoadFromFile({ fileName: inputFileName });
// Get the first worksheet
let sheet = workbook.Worksheets.get(0);
// Convert a specific cell range of the worksheet to image
let image = sheet.ToImage(5, 2, 17, 5);
// Specify the output image file path
const outputFileName = 'CellRangeToImage.png';
//Save the image
image.Save(outputFileName);
// Read the saved file and convert to Blob object
const modifiedFileArray = window.dotnetRuntime.Module.FS.readFile(outputFileName);
const modifiedFile = new Blob([modifiedFileArray], { type: 'image/png' });
// Create a URL for the Blob and initiate download
const url = URL.createObjectURL(modifiedFile);
const a = document.createElement('a');
a.href = url;
a.download = outputFileName;
document.body.appendChild(a);
a.click();
document.body.removeChild(a);
URL.revokeObjectURL(url);
// Clean up resources used by the workbook
workbook.Dispose();
}
};
return (
<div style={{ textAlign: 'center', height: '300px' }}>
<h1>Convert a Cell Range to Image Using JavaScript in React</h1>
<button onClick={ExcelToImage} disabled={!wasmModule}>
Convert
</button>
</div>
);
}
export default App;
Get a Free License
To fully experience the capabilities of Spire.XLS for JavaScript without any evaluation limitations, you can request a free 30-day trial license.
