Do you know how to generate PDFs for download?

<introEmbed body={<> Some projects call for being able to export data as a PDF. In these instances, it's great to be able to fully generate the file in the back-end and then provide it for download. As with most software problems, there's many ways to achieve the same end result, each with their pros and cons. </>} />

Paid libraries

There are many paid .NET libraries available which can generate PDFs for you like:

• PDFTron
• Syncfusion
• IronPDF

If the project has budget for a paid PDF solution, these are great and will get you generating PDFs quickly.

Pros:

✅ Mostly works out-of-the-box ✅ Potential for commercial support from the library developer

Cons:

❌ Project might not have the budget for such an option ❌ Is often closed source (see more)

Free libraries

Unfortunately, the vast majority of libraries which can generate PDFs directly are paid. To get around this, the PDF generation function of a browser testing library can be used instead. Using this method, the desired content is rendered in a headless browser and that browser is then used to generate a PDF.

Pros:

✅ Free! ✅ Open source ✅ Can easily reuse existing web layouts

Cons:

❌ Support is often limited ❌ May require more configuration to get working

Example

One library which makes this really easy (and is free!) is Playwright.

Generating a PDF here takes just a few lines, see the demo and docs for more info.

public async Task<byte[]> ExportView(string url, CancellationToken cancellationToken)
{
    var playwright = await Playwright.CreateAsync();
    var browser = await playwright.Chromium.LaunchAsync();
    var page = await browser.NewPageAsync();
    await page.GotoAsync(url);
    if (cancellationToken.IsCancellationRequested) { return Array.Empty<byte>(); }

    return await page.PdfAsync(new PagePdfOptions { Format = "A4" });
}

Figure: A simple method to return a PDF using Playwright