How to convert images to PDF in Node.js

In this tutorial, you’ll learn how to convert an image to a PDF using Node.js. In the first part, you’ll use the pdf-lib(opens in a new tab) library, and in the second part, you’ll use Nutrient Node.js SDK.

Prerequisites

Before you begin, make sure you have the following installed:

• Node.js(opens in a new tab) — You can download it from the official Node.js website.
• npm(opens in a new tab) — Node Package Manager comes bundled with Node.js, so it’ll be installed by default.

Step 1 — Setting up your project

1. Create a new directory for your project:

   mkdir image-to-pdf-converter
   cd image-to-pdf-converter

2. Initialize a new Node.js project:

   npm init -y

3. Install the pdf-lib library:

   npm install pdf-lib

Step 2 — Writing the conversion code

1. Create a file named convert.js in your project directory and add the following code:

   const fs = require("fs");
   const { PDFDocument } = require("pdf-lib");
   
   async function convertImageToPdf(imagePath, pdfPath) {
     // Read the image file asynchronously.
     const image = await fs.promises.readFile(imagePath);
   
     // Create a new PDF document.
     const pdfDoc = await PDFDocument.create();
   
     // Add a new page to the PDF document with a dimension of 400×400 points.
     const page = pdfDoc.addPage([400, 400]);
   
     // Embed the image into the PDF document.
     // Use embedPng() for PNG files, embedJpg() for JPEG files.
     const imageEmbed = imagePath.toLowerCase().endsWith(".png")
       ? await pdfDoc.embedPng(image)
       : await pdfDoc.embedJpg(image);
   
     // Scale the image to fit within the page dimensions while preserving aspect ratio.
     const { width, height } = imageEmbed.scaleToFit(
       page.getWidth(),
       page.getHeight(),
     );
   
     // Draw the image on the PDF page.
     page.drawImage(imageEmbed, {
       x: page.getWidth() / 2 - width / 2, // Center the image horizontally.
       y: page.getHeight() / 2 - height / 2, // Center the image vertically.
       width,
       height,
     });
   
     // Save the PDF document as bytes.
     const pdfBytes = await pdfDoc.save();
   
     // Write the PDF bytes to a file asynchronously.
     await fs.promises.writeFile(pdfPath, pdfBytes);
   }
   
   // Call the conversion function with input and output file paths.
   convertImageToPdf("input.jpg", "output.pdf")
     .then(() => {
       console.log("Image converted to PDF successfully!");
     })
     .catch((error) => {
       console.error("Error converting image to PDF:", error);
     });

2. Replace 'input.jpg' with the path to the image you want to convert (JPEG or PNG) and 'output.pdf' with the desired path for the output PDF.

3. Run the conversion script using the following command:

   node convert.js

Check your project directory for the generated output.pdf file.

You’ve successfully converted an image to a PDF using Node.js and the pdf-lib library.

Nutrient Node.js SDK

If you need more than basic image-to-PDF conversion, Nutrient Node.js SDK gives you a single dependency for all your document processing needs. Instead of juggling multiple libraries for different file types, you get one SDK that handles images, Office documents, and PDFs — with no MS Office installation required.

Why use Nutrient for image conversion?

• One SDK, multiple formats — Convert images today. Then use the same SDK to handle Word, Excel, and PowerPoint files tomorrow. No need to add new dependencies as your requirements grow.
• Production-ready output — Custom fonts are preserved automatically, so your converted PDFs look exactly as intended without extra configuration.
• Two-way conversion — Convert images to PDF, or render PDF pages back to PNG/WebP. Handle both directions with the same tool.
• No external dependencies — Skip installing MS Office, LibreOffice, or other converters on your server. Nutrient runs standalone.

When to choose Nutrient over pdf-lib

Integrating Nutrient Node.js SDK

1. Initialize a new Node.js project:

   npm init -y

   This command creates a package.json file in your project directory, which is essential for managing your project’s dependencies.

2. Install the Nutrient Node.js SDK package:

   npm install @nutrient-sdk/node

3. Place your image document (e.g. image.png) in your project directory.

4. Create a new JavaScript file named index.js in your project directory. This script handles the conversion.

   const { load } = require("@nutrient-sdk/node");
   const fs = require("fs");
   
   (async () => {
     const pngImage = fs.readFileSync("image.png");
   
     const instance = await load({ document: pngImage });
     const buffer = await instance.exportPDF();
   
     fs.writeFileSync("converted.pdf", Buffer.from(buffer));
     instance.close();
   })();

   This example reads the image file, converts it to PDF, and saves the result as converted.pdf in your project directory.

   Format	Supported
   PNG	✓
   JPEG, JPG	✓
   TIFF, TIF	✓

   By default, the resulting PDF will include a Nutrient watermark. To exclude the watermark, you can specify the license property with a key and appName when calling the load() function. For details on obtaining a trial license key, please get in touch with Sales.

5. Execute the script in your terminal to initiate the conversion process:

   node index.js

Conclusion

In this post, you learned two ways to convert images to PDF in Node.js. pdf-lib works well for straightforward image embedding. But if your project will eventually need Office document conversion, PDF rendering, or other document operations, Nutrient Node.js SDK lets you start with image conversion and scale to handle everything else — without adding more dependencies later.

To get started with Nutrient Node.js SDK:

• Start your free trial to test the SDK in your application.
• Try the demo to see document conversion in action.

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