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Convert HTML to PDF with Google Apps Script and FileSlap API

Convert HTML to PDF with Google Apps Script and FileSlap API

Automate PDF generation in Google Workspace using Apps Script and our powerful cloud-based API

July 10, 2025

Why Convert HTML to PDF with Google Apps Script?

Google Apps Script users need automated PDF generation for:

Google Sheets reports - Convert spreadsheet data to professional PDFs
Google Forms responses - Generate PDF summaries of form submissions
Gmail automation - Create PDFs from email content and send as attachments
Google Docs integration - Convert documents to PDFs for distribution
Drive automation - Generate PDFs and save them to Google Drive

While Google Apps Script has some basic PDF capabilities, they're limited in functionality and customization. The FileSlap API integration gives you unlimited flexibility to create professional, branded PDFs from any HTML content with advanced formatting and styling.

Setting Up Your FileSlap API Integration

1. Get Your API Key

First, sign up at fileslap.com and grab your API key. It's free to start with 50 conversions per month.

2. Configure Apps Script

Google Apps Script has built-in HTTP request capabilities, making it perfect for integrating with the FileSlap API.

Basic HTML to PDF Conversion

Here's the simplest way to convert HTML to PDF in Google Apps Script:

function convertHtmlToPdf(htmlContent, apiKey) {
  const url = 'https://api.fileslap.com/api/convert';
  
  const options = {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'X-API-KEY': apiKey
    },
    payload: JSON.stringify({
      html: htmlContent
    })
  };
  
  try {
    const response = UrlFetchApp.fetch(url, options);
    
    if (response.getResponseCode() === 200) {
      // Get the PDF as a blob
      const pdfBlob = response.getBlob();
      
      // Save to Google Drive
      const file = DriveApp.createFile(pdfBlob);
      file.setName('generated.pdf');
      
      Logger.log('PDF created successfully: ' + file.getUrl());
      return file;
    } else {
      Logger.log('Error: ' + response.getResponseCode());
      Logger.log('Response: ' + response.getContentText());
      return null;
    }
  } catch (error) {
    Logger.log('Request failed: ' + error.toString());
    return null;
  }
}

// Example usage
function testPdfConversion() {
  const htmlContent = `
    <!DOCTYPE html>
    <html>
    <head>
        <title>Sample Document</title>
        <style>
            body { font-family: Arial, sans-serif; margin: 40px; }
            h1 { color: #333; }
        </style>
    </head>
    <body>
        <h1>Hello from Google Apps Script!</h1>
        <p>This HTML was converted to PDF using the FileSlap API.</p>
    </body>
    </html>
  `;
  
  const apiKey = 'YOUR_API_KEY';
  const pdfFile = convertHtmlToPdf(htmlContent, apiKey);
  
  if (pdfFile) {
    Logger.log('PDF saved to Drive: ' + pdfFile.getUrl());
  }
}

Real-World Google Apps Script Examples

1. Google Sheets to PDF Report

Convert spreadsheet data to a professional PDF report:

function generateSheetReport() {
  const sheet = SpreadsheetApp.getActiveSheet();
  const data = sheet.getDataRange().getValues();
  
  // Create HTML table from sheet data
  let tableHtml = '<table style="width: 100%; border-collapse: collapse; margin: 20px 0;">';
  
  // Add header row
  tableHtml += '<thead><tr>';
  data[0].forEach(header => {
    tableHtml += `<th style="border: 1px solid #ddd; padding: 8px; text-align: left; background-color: #f2f2f2;">${header}</th>`;
  });
  tableHtml += '</tr></thead>';
  
  // Add data rows
  tableHtml += '<tbody>';
  for (let i = 1; i < data.length; i++) {
    tableHtml += '<tr>';
    data[i].forEach(cell => {
      tableHtml += `<td style="border: 1px solid #ddd; padding: 8px;">${cell}</td>`;
    });
    tableHtml += '</tr>';
  }
  tableHtml += '</tbody></table>';
  
  const htmlContent = `
    <!DOCTYPE html>
    <html>
    <head>
        <title>${sheet.getName()} Report</title>
        <style>
            body { font-family: Arial, sans-serif; margin: 40px; }
            .header { text-align: center; margin-bottom: 30px; }
            h1 { color: #333; }
        </style>
    </head>
    <body>
        <div class="header">
            <h1>${sheet.getName()} Report</h1>
            <p>Generated on ${new Date().toLocaleDateString()}</p>
        </div>
        ${tableHtml}
    </body>
    </html>
  `;
  
  const apiKey = PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
  const pdfFile = convertHtmlToPdf(htmlContent, apiKey);
  
  if (pdfFile) {
    pdfFile.setName(`${sheet.getName()}_Report_${new Date().toISOString().split('T')[0]}.pdf`);
    Logger.log('Report generated: ' + pdfFile.getUrl());
  }
}

2. Google Forms Response to PDF

Generate PDFs from form submissions:

function onFormSubmit(e) {
  const formResponse = e.response;
  const itemResponses = formResponse.getItemResponses();
  
  // Build HTML from form responses
  let formHtml = '<div style="font-family: Arial, sans-serif; margin: 40px;">';
  formHtml += '<h1>Form Submission Report</h1>';
  formHtml += '<p><strong>Submitted:</strong> ' + formResponse.getTimestamp() + '</p>';
  
  itemResponses.forEach(itemResponse => {
    const question = itemResponse.getItem().getTitle();
    const answer = itemResponse.getResponse();
    
    formHtml += `
      <div style="margin: 20px 0; padding: 15px; border: 1px solid #ddd; border-radius: 5px;">
        <h3 style="margin: 0 0 10px 0; color: #333;">${question}</h3>
        <p style="margin: 0; color: #666;">${answer}</p>
      </div>
    `;
  });
  
  formHtml += '</div>';
  
  const fullHtml = `
    <!DOCTYPE html>
    <html>
    <head>
        <title>Form Submission</title>
        <meta charset="utf-8">
    </head>
    <body>
        ${formHtml}
    </body>
    </html>
  `;
  
  const apiKey = PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
  const pdfFile = convertHtmlToPdf(fullHtml, apiKey);
  
  if (pdfFile) {
    pdfFile.setName(`Form_Submission_${formResponse.getTimestamp().toISOString().split('T')[0]}.pdf`);
    
    // Email the PDF to admin
    const adminEmail = '[email protected]';
    GmailApp.sendEmail(adminEmail, 'New Form Submission PDF', 
      'A new form submission has been converted to PDF and attached.', {
        attachments: [pdfFile.getBlob()],
        name: 'Form Submission System'
      });
  }
}

3. Gmail to PDF Archive

Convert emails to PDFs and save to Drive:

function archiveEmailsToPdf() {
  const threads = GmailApp.search('label:important', 0, 10); // Get last 10 important emails
  
  threads.forEach(thread => {
    const messages = thread.getMessages();
    
    messages.forEach(message => {
      const subject = message.getSubject();
      const body = message.getPlainBody();
      const date = message.getDate();
      
      const htmlContent = `
        <!DOCTYPE html>
        <html>
        <head>
            <title>${subject}</title>
            <style>
                body { font-family: Arial, sans-serif; margin: 40px; line-height: 1.6; }
                .header { border-bottom: 2px solid #333; padding-bottom: 20px; margin-bottom: 30px; }
                .email-body { white-space: pre-wrap; }
            </style>
        </head>
        <body>
            <div class="header">
                <h1>${subject}</h1>
                <p><strong>From:</strong> ${message.getFrom()}</p>
                <p><strong>Date:</strong> ${date.toLocaleString()}</p>
            </div>
            <div class="email-body">${body}</div>
        </body>
        </html>
      `;
      
      const apiKey = PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
      const pdfFile = convertHtmlToPdf(htmlContent, apiKey);
      
      if (pdfFile) {
        const safeSubject = subject.replace(/[^a-z0-9]/gi, '_');
        pdfFile.setName(`Email_${safeSubject}_${date.toISOString().split('T')[0]}.pdf`);
        
        // Move to archive folder
        const archiveFolder = DriveApp.getFolderById('YOUR_ARCHIVE_FOLDER_ID');
        archiveFolder.addFile(pdfFile);
        DriveApp.getRootFolder().removeFile(pdfFile);
      }
    });
  });
}

Advanced Google Apps Script Configurations

Error Handling and Retries

function convertWithRetry(htmlContent, apiKey, maxRetries = 3) {
  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      const result = convertHtmlToPdf(htmlContent, apiKey);
      
      if (result) {
        return result;
      }
      
      // Wait before retry
      if (attempt < maxRetries) {
        Utilities.sleep(2000 * attempt); // Exponential backoff
      }
      
    } catch (error) {
      Logger.log(`Attempt ${attempt} failed: ${error.toString()}`);
      
      if (attempt === maxRetries) {
        throw error;
      }
    }
  }
  
  return null;
}

Batch Processing

function batchConvertToPdf(htmlTemplates) {
  const results = [];
  
  htmlTemplates.forEach((template, index) => {
    try {
      const apiKey = PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
      const pdfFile = convertHtmlToPdf(template.html, apiKey);
      
      if (pdfFile) {
        pdfFile.setName(template.filename || `document_${index + 1}.pdf`);
        results.push({
          success: true,
          file: pdfFile,
          index: index
        });
      } else {
        results.push({
          success: false,
          error: 'PDF generation failed',
          index: index
        });
      }
      
      // Add delay between requests to avoid rate limiting
      Utilities.sleep(1000);
      
    } catch (error) {
      results.push({
        success: false,
        error: error.toString(),
        index: index
      });
    }
  });
  
  return results;
}

Template Engine

function generateInvoicePdf(orderData) {
  const template = `
    <!DOCTYPE html>
    <html>
    <head>
        <title>Invoice #{{orderNumber}}</title>
        <style>
            body { font-family: Arial, sans-serif; margin: 40px; }
            .header { text-align: center; border-bottom: 2px solid #333; padding-bottom: 20px; }
            .invoice-details { margin: 30px 0; }
            .items-table { width: 100%; border-collapse: collapse; margin: 20px 0; }
            .items-table th, .items-table td { border: 1px solid #ddd; padding: 8px; text-align: left; }
            .total { font-weight: bold; font-size: 18px; text-align: right; }
        </style>
    </head>
    <body>
        <div class="header">
            <h1>INVOICE</h1>
            <p>Order #{{orderNumber}} | Date: {{orderDate}}</p>
        </div>
        
        <div class="invoice-details">
            <h3>Bill To:</h3>
            <p>{{customerName}}<br>
            {{customerEmail}}<br>
            {{customerAddress}}</p>
        </div>
        
        <table class="items-table">
            <thead>
                <tr>
                    <th>Item</th>
                    <th>Quantity</th>
                    <th>Price</th>
                    <th>Total</th>
                </tr>
            </thead>
            <tbody>
                {{#each items}}
                <tr>
                    <td>{{name}}</td>
                    <td>{{quantity}}</td>
                    <td>${{price}}</td>
                    <td>${{total}}</td>
                </tr>
                {{/each}}
            </tbody>
        </table>
        
        <div class="total">
            <p>Total: ${{total}}</p>
        </div>
    </body>
    </html>
  `;
  
  // Simple template replacement
  let html = template;
  html = html.replace(/{{orderNumber}}/g, orderData.orderNumber);
  html = html.replace(/{{orderDate}}/g, orderData.orderDate);
  html = html.replace(/{{customerName}}/g, orderData.customerName);
  html = html.replace(/{{customerEmail}}/g, orderData.customerEmail);
  html = html.replace(/{{customerAddress}}/g, orderData.customerAddress);
  html = html.replace(/{{total}}/g, orderData.total);
  
  // Replace items
  const itemsHtml = orderData.items.map(item => 
    `<tr><td>${item.name}</td><td>${item.quantity}</td><td>$${item.price}</td><td>$${item.quantity * item.price}</td></tr>`
  ).join('');
  
  html = html.replace(/{{#each items}}[\s\S]*?{{\/each}}/, itemsHtml);
  
  const apiKey = PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
  return convertHtmlToPdf(html, apiKey);
}

Setting Up API Key Security

Store your API key securely using Apps Script Properties:

// Set the API key (run this once)
function setupApiKey() {
  PropertiesService.getScriptProperties().setProperty('FILESLAP_API_KEY', 'your_api_key_here');
}

// Get the API key in your functions
function getApiKey() {
  return PropertiesService.getScriptProperties().getProperty('FILESLAP_API_KEY');
}

Popular Google Apps Script + FileSlap Use Cases

Google Workspace Automation

Sheets Reports: Convert spreadsheet data to PDF reports
Forms Processing: Generate PDF summaries of form responses
Gmail Archiving: Convert important emails to PDFs
Docs Integration: Convert Google Docs to PDFs
Drive Organization: Automatically organize PDFs in Drive

Business Workflows

Invoice Generation: Create PDF invoices from order data
Report Distribution: Email PDF reports to stakeholders
Document Archiving: Convert documents to PDFs for long-term storage
Data Export: Export Google Sheets data as formatted PDFs

Performance Tips

1. Batch Processing

Process multiple documents in batches
Add delays between requests to avoid rate limiting
Use try-catch blocks for error handling

2. Caching

Cache frequently used templates
Store generated PDFs in Drive for reuse
Use Apps Script Properties for configuration

3. Error Handling

Implement retry logic for failed requests
Log errors for debugging
Send notifications for critical failures

Troubleshooting Common Issues

HTTP Request Errors

Problem: API requests failing Solution: Check API key, network connectivity, and request format

Rate Limiting

Problem: Too many requests Solution: Add delays between requests and implement exponential backoff

Large HTML Content

Problem: Timeout errors with large documents Solution: Break large documents into smaller chunks

Get Started Today

Ready to automate PDF generation in Google Workspace?

Sign up at fileslap.com
Get your API key from the dashboard
Open Google Apps Script and create a new project
Copy the code examples above and customize for your needs
Test with a simple conversion before building complex workflows

No external dependencies required - just Google Apps Script and the FileSlap API.

Need Help?

Documentation: fileslap.com/docs
Google Apps Script Documentation: developers.google.com/apps-script
Support: Reach out to our team for custom integration help

Transform your Google Workspace workflows with automated PDF generation using Apps Script and FileSlap.

Tags: #GoogleAppsScript #PDF #API #GoogleWorkspace #Automation #FileSlap #GSuite