Convert XLS to XLSX

NodeJS library for converting XLS to XLSX

Use the Conversion API of of Cells Cloud to create customized spreadsheet workflows in NodeJS projects. This is a professional solution to convert XLS to XLSX and other document formats online using NodeJS.

Convert XLS to XLSX using Cells Cloud SDK for NodeJS


Converting file formats from XLS to XLSX can be a complex task. Our NodeJS SDK handles all XLS to XLSX format conversions while preserving the main structural and logical content of the source XLS spreadsheet. Our NodeJS library provides a professional solution for converting XLS to XLSX files online. This Cloud SDK empowers NodeJS developers with powerful functionality and ensures high-quality XLSX output.

NodeJS Code Example for converting XLS to XLSX using Cells Cloud SDK

// For complete examples and data files, please go to
    const { CellsApi, CellsWorkbook_PutConvertWorkbookRequest } = require("asposecellscloud");
    const localPath = "../TestData/source/";
    var fs = require('fs');
    var path = require('path');
    const cellsApi = new CellsApi(process.env.ProductClientId, process.env.ProductClientSecret);
    var req = new CellsWorkbook_PutConvertWorkbookRequest({
        file: fs.createReadStream(localPath + "datasource.xls"),
        format: "xlsx",
        .then((result) => {

How to convert XLS to XLSX using the Cells Cloud NodeJS library.

  1. Register an account at Dashboard to get free API quota & authorization details
  2. Install NodeJS library and add the reference (import the library) to your project.
  3. Open the source file in JavaScript.
  4. Use the `putConvertWorkbook` method to retrieve the resulting stream.

System Requirements

  1. node v6.17.1 or newer