Best Free Excel Libraries for C++ Windows

The best free library for working with Excel in C++ for Windows I would recommend is OpenXLSX. This is an open-source library under the GPL license that provides complete reading, writing, and creation of Excel files (.xlsx), including formula support. OpenXLSX is a cross-platform solution with active development and good documentation.

Table of Contents

• What is OpenXLSX
• Main Library Features
• Installation and Setup
• Usage Examples
• Alternative Options
• Limitations and Features

What is OpenXLSX

OpenXLSX is an open-source C++ library for reading, writing, creating, and modifying Microsoft Excel (.xlsx) files. As stated in the project documentation, this library was developed to address the lack of mature open-source libraries for working with Excel in C++.

The OpenXLSX library supports several important functions, such as creating, opening, and saving spreadsheet files, reading and writing data.

Key features:

• Completely free and open-source
• GPL (General Public License) license
• Cross-platform support (Windows, Linux, macOS)
• Works with the modern .xlsx format
• Does not require Microsoft Excel installation

Main Library Features

Reading and Writing Data Support

OpenXLSX provides full access to Excel cells:

#include <OpenXLSX.hpp>

using namespace OpenXLSX;

int main() {
    // Opening an existing Excel file
    XLDocument doc;
    doc.open("example.xlsx");
    
    auto wks = doc.workbook().worksheet("Sheet1");
    
    // Reading data from cells
    auto cellValue = wks.cell("A1").value();
    std::cout << "Cell A1 value: " << cellValue << std::endl;
    
    // Writing data to cells
    wks.cell("B1").value("Hello, world!");
    wks.cell("C1").value(42);
    wks.cell("D1").value(3.14);
    
    doc.save();
    doc.close();
    return 0;
}

Formula Support

The library supports working with Excel formulas:

// Setting a formula in a cell
wks.cell("E1").value("=SUM(A1:D1)");

// Getting the formula value
auto formulaResult = wks.cell("E1").value();
std::cout << "Formula result: " << formulaResult << std::endl;

Additional Features

• Managing workbooks and worksheets
• Reading and writing formatting styles
• Working with cell ranges
• Support for different data types (strings, numbers, dates, boolean values)
• Data export and import

Installation and Setup

System Requirements

• C++17 or higher
• CMake 3.15 or higher
• Modern compiler (MSVC 2019+, GCC 7+, Clang 6+)

Installation Process

1. Cloning the repository from GitHub:

git clone https://github.com/troldal/OpenXLSX.git
cd OpenXLSX

2. Building the project with CMake:

mkdir build
cd build
cmake ..
cmake --build .

3. Integration into Visual Studio project:

• Add the include directory to additional include directories
• Reference the built libraries in the linker settings

Example CMakeLists.txt for your project:

cmake_minimum_required(VERSION 3.15)
project(MyExcelApp)

set(CMAKE_CXX_STANDARD 17)

# Adding OpenXLSX
add_subdirectory(third_party/OpenXLSX)

# Creating your application
add_executable(myapp main.cpp)
target_link_libraries(myapp OpenXLSX)

Usage Examples

Creating a New Excel File

#include <OpenXLSX.hpp>

void createExcelFile() {
    // Creating a new document
    XLDocument doc;
    doc.create("new_file.xlsx");
    
    // Getting the workbook and worksheet
    auto wks = doc.workbook().worksheet("Sheet1");
    
    // Writing headers
    wks.cell("A1").value("Product");
    wks.cell("B1").value("Quantity");
    wks.cell("C1").value("Price");
    wks.cell("D1").value("Amount");
    
    // Writing data
    wks.cell("A2").value("Apples");
    wks.cell("B2").value(10);
    wks.cell("C2").value(50.0);
    wks.cell("D2").value("=B2*C2");
    
    wks.cell("A3").value("Oranges");
    wks.cell("B3").value(15);
    wks.cell("C3").value(75.0);
    wks.cell("D3").value("=B3*C3");
    
    // Saving and closing
    doc.save();
    doc.close();
}

Reading and Processing Data

void readExcelData() {
    XLDocument doc;
    doc.open("data.xlsx");
    
    auto wks = doc.workbook().worksheet("Sheet1");
    
    // Reading the number of rows
    auto lastRow = wks.rowCount();
    
    // Processing data
    for (XLRow row : wks.rows()) {
        auto productName = row.cell(1).value();
        auto quantity = row.cell(2).value();
        auto price = row.cell(3).value();
        
        std::cout << "Product: " << productName 
                  << ", Quantity: " << quantity 
                  << ", Price: " << price << std::endl;
    }
    
    doc.close();
}

Alternative Options

LibXL

LibXL is another popular library for working with Excel:

• Pros:

  • Supports .xls and .xlsx formats
  • High performance
  • Ease of use

• Cons:

  • Not completely free - has limitations in the free version (up to 300 operations simultaneously)
  • License is not GPL, but commercial
  • The first row cannot be read or written in the free version

Aspose.Cells for C++

Aspose.Cells is a powerful commercial library:

• Pros:

  • Full support for all Excel features
  • Excellent documentation
  • Technical support

• Cons:

  • Paid - no free version
  • License is not GPL

Limitations and Features

Advantages of OpenXLSX

• Completely free under GPL license
• Open source - can be modified and adapted
• Modern format .xlsx support
• Cross-platform - works on Windows, Linux, macOS
• Active development - regular updates

Current Limitations

• Only .xlsx format support (not .xls)
• Some complex Excel features may have limited support
• Documentation may not be as complete as commercial alternatives

Usage Tips

1. Start with simple read/write operations
2. Use examples from the GitHub repository
3. Keep track of library updates
4. If you encounter problems, refer to the issue tracker on GitHub

Conclusion

OpenXLSX is the best choice for free Excel work in C++ on Windows, especially when the GPL license is important. The library provides:

1. Full read and write access to Excel cell data
2. Formula support for calculations
3. Free use without operation quantity limitations
4. Compatibility with modern Excel versions
5. Active community and development

For most Excel automation tasks in C++, OpenXLSX provides sufficient functionality while remaining completely free and open-source.

Sources

1. Open Source C++ Library for Spreadsheets — Reading and Writing Excel Files
2. GitHub - OpenXLSX: A C++ library for reading, writing, creating and modifying Microsoft Excel® (.xlsx) files
3. C++ library to read Excel Spreadsheets - Software Recommendations Stack Exchange
4. C++ Excel Library to read/write xls/xlsx files - LibXL
5. Library for working with Excel format
6. Creating Excel files in C++ | Creating charts, formulas, tables in Excel files