Avoiding Common Pitfalls in PDF Generation: Lessons from reportgen.io Users 🚧

February 25, 2025

PDF generation should be simple, but as many developers quickly realize, it's full of pitfalls—from broken layouts to performance bottlenecks. The good news? reportgen.io users have already solved these problems.

Today, we're diving into the most common mistakes in PDF generation and sharing battle-tested solutions from developers using reportgen.io.

1️⃣ Performance Pitfalls: Sluggish and Unscalable PDF Generation

🚨 The Problem: Slow or Resource-Intensive PDFs

PDF generation often becomes a bottleneck, especially when dealing with large datasets, complex templates, or high request volumes. Some common issues include:

Blocking API Calls: Generating PDFs synchronously slows down web requests.
Resource Overload: High-memory usage from HTML-to-PDF rendering.
Poor Caching Strategies: Re-generating unchanged reports wastes resources.

“We were generating PDFs on-demand, and it was killing our API response times." — Alex R., SaaS Founder

✅ The Fix: Use Asynchronous and Scalable Processing

reportgen.io users optimize performance by:

✅ Switching to asynchronous PDF generation (/generate-pdf-async endpoint).
✅ Batch-processing reports instead of generating PDFs per request.
✅ Leveraging caching for frequently generated reports.

🔹 Example API Call (Asynchronous PDF Generation)

curl -X POST "https://reportgen.io/api/v1/generate-pdf-async" \
-H "X-API-Key: YOUR_ACCESS_KEY" \
-H "Content-Type: application/json" \
-d '{
  "html_template": "<h1>Report for <%= Company %></h1><p>Revenue: $<%= Revenue %></p>",
  "data": { "Company": "Acme Corp", "Revenue": "1,250,000" },
  "engine": "ejs"
}'

2️⃣ Broken Formatting: Why Your PDFs Look Off

🚨 The Problem: Fonts, Images, and Layouts Don’t Render Correctly

Developers often run into misaligned elements, missing fonts, and distorted images due to:

Browser inconsistencies: HTML-to-PDF rendering doesn't match the web view.
Missing assets: External CSS, images, and fonts don’t load in headless environments.
Poorly structured HTML: Div-based layouts break inside PDFs.

“We thought our HTML template looked perfect—until we saw the generated PDF." — Lisa T., Engineering Lead

✅ The Fix: Use CSS Best Practices & Embed All Assets

To avoid formatting nightmares, reportgen.io users follow these best practices:

✅ Use absolute URLs for images, fonts, and CSS.
✅ Avoid CSS animations and flexbox-heavy layouts—stick to simple, table-based structures.
✅ Embed fonts directly in the HTML.

🔹 Example: Proper Image and Font Embedding

<style>
  @font-face {
    font-family: 'CustomFont';
    src: url('https://yourdomain.com/fonts/custom-font.woff2') format('woff2');
  }
  body { font-family: 'CustomFont', sans-serif; }
</style>
 
<img src="https://yourdomain.com/images/logo.png" width="200" />

3️⃣ Templating Chaos: Handling Dynamic Data Incorrectly

🚨 The Problem: Messy or Non-Functional Data Insertion

Developers using inconsistent syntax or mixing templating engines often find:

Unrendered variables (e.g., {{variable}} instead of <%= variable %>).
Data formatting issues (e.g., dates/numbers displaying incorrectly).
Security risks (e.g., unescaped user input leading to HTML injection).

"We accidentally used Handlebars syntax in an EJS template—nothing worked." — David P., Full-Stack Developer

✅ The Fix: Choose the Right Templating Engine & Stick to It

reportgen.io supports multiple engines, but you must be consistent:

✅ Use Handlebars ({{variable}}) for logic-less templates.
✅ Use EJS (<%= variable %>) for JavaScript-based templates.
✅ Use GoTempl ({{.Variable}}) if you're working in Go.

🔹 Example: Correct Handlebars vs. EJS Syntax

<!-- Handlebars -->
<h1>Hello, {{name}}!</h1>
<p>Total: {{total}}</p>

<!-- EJS -->
<h1>Hello, <%= name %>!</h1>
<p>Total: <%= total %></p>

4️⃣ Security Risks: Protecting Sensitive PDF Data

🚨 The Problem: Exposing API Keys & Storing PDFs Unsafely

Security is often overlooked, leading to:

Hardcoded API keys in public repositories.
Unencrypted PDF storage that leaks user data.
Unrestricted API access, leading to abuse.

“One of our developers accidentally pushed an API key to GitHub. Disaster." — Michael S., CTO

✅ The Fix: Secure API Usage & Encrypted Storage

reportgen.io provides built-in security features:

✅ Use environment variables to store API keys securely.
✅ Restrict API access with IP whitelisting and scoped keys.
✅ Leverage signed URLs to control PDF access.

🔹 Example: Using an Environment Variable for API Keys

const API_KEY = process.env.REPORTGEN_API_KEY;

🚀 Avoid These Mistakes & Build Better PDF Workflows

By learning from real-world reportgen.io users, you can avoid the most common PDF generation pitfalls and create faster, more reliable, and more secure document workflows.

🔹 Ready to improve your PDF generation process?

What’s the biggest PDF generation challenge you've faced? Drop us a message! 🚀