How to convert HTML to PDF using web API in .NET?

The Syncfusion® HTML to PDF converter is a .NET library for converting webpages, SVG, MHTML and HTML to PDF using C#. It is reliable and accurate. The result preserves all graphics, images, text, fonts, and the layout of the original HTML document or webpage.

Using this library, you can convert the HTML to PDF using the Web API.

Steps to convert the HTML to PDF using the Web API programmatically:

1. Create a new ASP.NET Web application project.

2. Install the Syncfusion.HtmlToPdfConverter.AspNet.MVC5 NuGet package as a reference to your .NET Framework applications from NuGet.org.

3. Add a button to convert the HTML to PDF in index.cshtml.

   <div class="jumbotron">
   <h1>ASP.NET</h1>
   <input type="submit" value="Generate PDF" class="Button" id="btn1" onclick="HtmlToPDF()" />
   <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
    
   <script type="text/javascript">
   $('#btn1').click(function HtmlToPDF () {
          $.ajax({
                   url: 'http://localhost:62944/api/values?url=http://www.google.com',
                   type: "GET",
                   success: function (data) {
                       var filename = "HtmlToPDF.pdf";
                       if (window.navigator && window.navigator.msSaveOrOpenBlob) {
                             // IE and Edge version
                           var byteCharacters = atob(data);
                           var byteNumbers = new Array(byteCharacters.length);
                           for (var i = 0; i < byteCharacters.length; i++) {
                               byteNumbers[i] = byteCharacters.charCodeAt(i);
                           }
                           var byteArray = new Uint8Array(byteNumbers);
                           var blob = new Blob([byteArray], { type: 'application/pdf' });
                           window.navigator.msSaveOrOpenBlob(blob, filename);
    
                       }
                       else if (typeof window.chrome !== 'undefined') {
                           // Chrome version
                           var pdfAsDataUri = "data:application/pdf;base64, " + data;
                           var a = document.createElement('a');
                           a.href = pdfAsDataUri;
                           a.type = 'application/pdf';
                           a.download = filename;
                           a.click();
                       } else {
                           // Firefox version
                           window.open("data:application/pdf;base64, " + data);
                       }
                   }
               });
           });
   </script>
   </div>
   

4. Include the following namespaces in the ValuesController.cs file.

C#

using Syncfusion.HtmlConverter;
using Syncfusion.Pdf;
using System.IO;
using System.Web.Hosting;

5. Include the following code snippet in ValuesController.cs to convert HTML to PDF document.

   public string Get(string url)
   {
         byte[] data = HTMLtoPDF(url);
         return Convert.ToBase64String(data);
   }
   public byte[] HTMLtoPDF(string url)
   {
       //Initialize the HTML to PDF converter
       HtmlToPdfConverter htmlConverter = new HtmlToPdfConverter();
    
        //Convert URL to PDF document 
        PdfDocument document = htmlConverter.Convert(url);
    
        //Creates memory stream 
        MemoryStream stream = new MemoryStream();
    
        //Save and close the PDF document 
        document.Save(stream);
        document.Close(true);
    
        return stream.ToArray();
   }
   

A complete working sample can be downloaded from HTML-to-PDF-WebAPI.zip.

By executing the program, you will get the PDF file as follows.

Take a moment to peruse the documentation, where you can find converting HTML pages to PDF document along with respective customization options and features.

Click here to explore the rich set of Syncfusion Essential® PDF features.

An online sample link to Convert Html To PDF document.