Tutorial: How to Convert PDF to HTML Format

Learning Objectives

In this tutorial, you’ll learn how to:

  • Convert PDF documents to HTML format using Aspose.PDF Cloud API
  • Customize the HTML output with various conversion parameters
  • Implement PDF to HTML conversion in multiple programming languages
  • Handle embedded resources like images, fonts, and CSS
  • Troubleshoot common conversion issues

Prerequisites

Before starting this tutorial, make sure you have:

  • An Aspose Cloud account (sign up for a free trial if needed)
  • Your Client ID and Client Secret credentials
  • Basic understanding of REST APIs and HTML
  • Familiarity with your preferred programming language (C#, Java, Python, etc.)
  • A PDF document ready for conversion

Introduction

Converting PDF documents to HTML is essential when you need to:

  • Make PDF content accessible on the web
  • Create responsive versions of fixed-layout documents
  • Integrate PDF content into existing websites
  • Enable better search engine indexing of document content

Aspose.PDF Cloud API provides powerful tools to convert PDFs to well-structured HTML while preserving formatting, images, and layout as much as possible.

Why Convert PDF to HTML?

  • Web Accessibility: Make document content available online in a format compatible with all devices
  • Content Integration: Easily integrate PDF content into existing web pages
  • Responsive Design: Adapt fixed-layout PDFs to responsive web design principles
  • SEO Benefits: HTML content is more easily indexed by search engines than PDF content
  • Content Editing: HTML is easier to edit and maintain than PDF

Tutorial Overview

This tutorial covers the following approaches for PDF to HTML conversion:

  1. Converting a PDF document stored in cloud storage to HTML and getting the result
  2. Converting a PDF document stored in cloud storage to HTML and saving the result to storage
  3. Uploading a PDF document in the request and converting it to HTML
  4. Customizing HTML output with conversion parameters

Let’s get started!

1. Authentication

Before making any API calls, you need to obtain an authentication token:

Try it yourself:

curl -v "https://api.aspose.cloud/connect/token" \
-X POST \
-d "grant_type=client_credentials&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET" \
-H "Content-Type: application/x-www-form-urlencoded" \
-H "Accept: application/json"

Replace YOUR_CLIENT_ID and YOUR_CLIENT_SECRET with your actual credentials. The response will provide an access token that you’ll use in subsequent API calls.

2. Converting a PDF Document from Storage to HTML

In this approach, we’ll convert a PDF document that’s already uploaded to your Aspose Cloud Storage.

Step 1: Upload a PDF document to storage (if not already done)

curl -X PUT "https://api.aspose.cloud/v3.0/pdf/storage/file/Sample.pdf" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
-H "Content-Type: multipart/form-data" \
-T /path/to/your/Sample.pdf

Step 2: Convert the PDF to HTML and get the result in response

cURL Example:

curl -v "https://api.aspose.cloud/v3.0/pdf/Sample.pdf/convert/html" \
-X GET \
-H "Accept: multipart/form-data" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
-o result.html

Try it yourself:

  1. Replace YOUR_ACCESS_TOKEN with the token you received during authentication
  2. Run the command and check the resulting HTML file
  3. Open it in a browser to see how well the conversion preserved the original formatting

3. Converting a PDF Document from Storage to HTML with Resources

When converting to HTML, you often need to handle embedded resources like images. This approach saves the HTML and its resources to storage:

cURL Example:

curl -v "https://api.aspose.cloud/v3.0/pdf/Sample.pdf/convert/html?outPath=result.html" \
-X PUT \
-H "Accept: application/json" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN"

Try it yourself:

  1. Replace YOUR_ACCESS_TOKEN with your token
  2. Run the command and verify in your storage dashboard that the HTML file and resource folder were created

4. Customizing HTML Output with Conversion Parameters

Aspose.PDF Cloud API offers various parameters to customize the HTML output. Here’s how to use them:

cURL Example with Custom Parameters:

curl -v "https://api.aspose.cloud/v3.0/pdf/Sample.pdf/convert/html?outPath=result_custom.html&width=800&fixedLayout=true&splitCssIntoPages=true" \
-X PUT \
-H "Accept: application/json" \
-H "Authorization: Bearer YOUR_ACCESS_TOKEN"

Key Parameters Explained:

  • width: Sets the page width in pixels (default is 800)
  • fixedLayout: Preserves the PDF layout in HTML (default is false)
  • splitCssIntoPages: Creates separate CSS for each page (default is true)
  • embedResources: Embeds resources like images in the HTML (default is false)

Try it yourself:

  1. Experiment with different parameter combinations to see their effect on the output
  2. Compare the results with and without fixedLayout to see the difference in responsiveness

SDK Examples

C# Example

// Import required namespaces
using System;
using System.IO;
using Aspose.Pdf.Cloud.Sdk.Api;
using Aspose.Pdf.Cloud.Sdk.Client;
using Aspose.Pdf.Cloud.Sdk.Model;

namespace PdfToHtmlExample
{
    class Program
    {
        static void Main(string[] args)
        {
            // Configure API client
            var config = new Configuration
            {
                ClientId = "YOUR_CLIENT_ID",
                ClientSecret = "YOUR_CLIENT_SECRET"
            };
            
            // Initialize PDF API
            var pdfApi = new PdfApi(config);
            
            try
            {
                // Convert PDF to HTML and save to storage with custom options
                var htmlOptions = new HtmlExportOptions
                {
                    FixedLayout = true,
                    SplitCssIntoPages = true,
                    EmbedResources = false,
                    Width = 800
                };
                
                var response = pdfApi.PutPdfInStorageToHtml(
                    "Sample.pdf",           // PDF document name in storage
                    "result_custom.html",   // Output HTML filename
                    htmlOptions,            // HTML export options
                    storage: null,          // Storage name (default)
                    folder: null            // Folder (root)
                );
                
                Console.WriteLine("PDF converted to HTML successfully! Status: " + response.Status);
                
                // Method 2: Convert PDF from storage to HTML and get the result
                var resultStream = pdfApi.GetPdfInStorageToHtml(
                    "Sample.pdf",           // PDF document name in storage
                    htmlOptions,            // HTML export options
                    storage: null,          // Storage name (default)
                    folder: null            // Folder (root)
                );
                
                // Save the result to a local file
                using (var fileStream = File.Create("local_result.html"))
                {
                    resultStream.CopyTo(fileStream);
                }
                
                Console.WriteLine("PDF converted to HTML and saved locally!");
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error converting PDF to HTML: " + ex.Message);
            }
        }
    }
}

Python Example

# Import the required modules
import asposepdfcloud
from asposepdfcloud.apis.pdf_api import PdfApi
from asposepdfcloud.api_client import ApiClient
from asposepdfcloud.configuration import Configuration
from asposepdfcloud.models.html_export_options import HtmlExportOptions

# Set up the API client
configuration = Configuration(client_id="YOUR_CLIENT_ID", client_secret="YOUR_CLIENT_SECRET")
api_client = ApiClient(configuration)
pdf_api = PdfApi(api_client)

try:
    # Create HTML export options
    html_options = HtmlExportOptions(
        fixed_layout=True,
        split_css_into_pages=True,
        embed_resources=False,
        width=800
    )
    
    # Method 1: Convert PDF from storage to HTML and save to storage
    response = pdf_api.put_pdf_in_storage_to_html(
        name="Sample.pdf",           # PDF document name in storage
        out_path="result_custom.html", # Output HTML filename
        html_export_options=html_options, # HTML export options
        storage=None,                # Storage name (default)
        folder=None                  # Folder (root)
    )
    
    print(f"PDF converted to HTML successfully! Status: {response.status}")
    
    # Method 2: Convert PDF from storage to HTML and get the result
    result_stream = pdf_api.get_pdf_in_storage_to_html(
        name="Sample.pdf",           # PDF document name in storage
        html_export_options=html_options, # HTML export options
        storage=None,                # Storage name (default)
        folder=None                  # Folder (root)
    )
    
    # Save the result to a local file
    with open("local_result.html", "wb") as file:
        file.write(result_stream)
    
    print("PDF converted to HTML and saved locally!")
    
except Exception as e:
    print(f"Error converting PDF to HTML: {str(e)}")

Java Example

// Import required packages
import com.aspose.pdf.cloud.sdk.api.PdfApi;
import com.aspose.pdf.cloud.sdk.model.*;
import com.aspose.pdf.cloud.sdk.invoker.*;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;

public class PdfToHtmlExample {
    public static void main(String[] args) {
        // Setup API client
        ApiClient apiClient = new ApiClient("YOUR_CLIENT_ID", "YOUR_CLIENT_SECRET");
        PdfApi pdfApi = new PdfApi(apiClient);
        
        try {
            // Create HTML export options
            HtmlExportOptions htmlOptions = new HtmlExportOptions();
            htmlOptions.setFixedLayout(true);
            htmlOptions.setSplitCssIntoPages(true);
            htmlOptions.setEmbedResources(false);
            htmlOptions.setWidth(800);
            
            // Method 1: Convert PDF from storage to HTML and save to storage
            AsposeResponse response = pdfApi.putPdfInStorageToHtml(
                "Sample.pdf",           // PDF document name in storage
                "result_custom.html",   // Output HTML filename
                htmlOptions,            // HTML export options
                null,                   // Storage name (default)
                null                    // Folder (root)
            );
            
            System.out.println("PDF converted to HTML successfully! Status: " + response.getStatus());
            
            // Method 2: Convert PDF from storage to HTML and get the result
            File resultFile = new File("local_result.html");
            InputStream resultStream = pdfApi.getPdfInStorageToHtml(
                "Sample.pdf",           // PDF document name in storage
                htmlOptions,            // HTML export options
                null,                   // Storage name (default)
                null                    // Folder (root)
            );
            
            // Save the result to a local file
            FileOutputStream outputStream = new FileOutputStream(resultFile);
            byte[] buffer = new byte[1024];
            int bytesRead;
            while ((bytesRead = resultStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }
            outputStream.close();
            resultStream.close();
            
            System.out.println("PDF converted to HTML and saved locally!");
            
        } catch (Exception e) {
            System.err.println("Error converting PDF to HTML: " + e.getMessage());
            e.printStackTrace();
        }
    }
}

HTML Output Customization Tips

For best results when converting PDF to HTML, consider these tips:

  1. Fixed vs. Responsive Layout

    • Use fixedLayout=true for a pixel-perfect representation of the PDF
    • Use fixedLayout=false for responsive HTML that adapts to different screen sizes

  2. Image Handling

    • Use embedResources=true to embed images directly in the HTML (larger file size but self-contained)
    • Use embedResources=false to create separate image files (better for web optimization)

  3. CSS Handling

    • splitCssIntoPages=true creates separate CSS for each page, which is good for complex documents
    • splitCssIntoPages=false creates a single CSS file, better for simpler documents and web optimization

  4. Page Width

    • Adjust the width parameter to match your target display size
    • Larger values provide more detail but may require horizontal scrolling

Troubleshooting

Common Issues and Solutions

  1. Resource Loading Issues

    • If images or styles aren’t loading, check that all resource files were properly extracted
    • When using embedResources=false, ensure the resource folder path is correctly referenced

  2. Layout Problems

    • Complex PDF layouts might not convert perfectly to HTML
    • Try using fixedLayout=true for better layout preservation

  3. Font Issues

    • Some fonts may not render correctly if they’re not web-safe
    • Consider using web-safe fonts or embedding them if needed

  4. Large Document Handling

    • For very large PDFs, consider converting page by page or sections at a time
    • Use the “save to storage” approach for large documents instead of direct response

Learning Checkpoint

Before continuing, make sure you understand:

  • How to authenticate with the Aspose.PDF Cloud API
  • The different methods for converting PDF to HTML
  • How to customize the HTML output using export options
  • How to handle resources like images and CSS

What You’ve Learned

In this tutorial, you’ve learned how to:

  • Convert PDF documents to HTML format using Aspose.PDF Cloud API
  • Customize the HTML output with various conversion parameters
  • Implement PDF to HTML conversion in multiple programming languages
  • Handle embedded resources like images, fonts, and CSS
  • Troubleshoot common conversion issues

Further Practice

To reinforce your learning, try these exercises:

  1. Convert a PDF with images and tables to HTML with both fixed and responsive layouts
  2. Create a web application that allows users to upload PDFs and view them as HTML
  3. Experiment with different export options to find the optimal balance between fidelity and web optimization
  4. Try converting a multi-page document and implement page navigation in the resulting HTML

Helpful Resources