How to convert Excel to PDF using JavaScript

Convert Excel files to PDFs in JavaScript using Nutrient DWS Processor’s XLSX-to-PDF JavaScript API. The free plan includes 200 credits. Different operations consume different amounts of credits. Create a free account(opens in a new tab) to get your API key.

It’s now possible to view and edit Word, Excel, and PowerPoint documents directly in the browser, without any server-side processing required.

Why convert Excel to PDF?

Converting Excel files to PDF is essential for workflows requiring document standardization and sharing. Common use cases include:

• Document preservation — Convert spreadsheets to PDFs to preserve formatting, formulas, and layouts regardless of software or device used to view them.
• Professional reporting — Generate polished financial reports, invoices, and data summaries that maintain consistent appearance across platforms.
• Compliance and archiving — Create tamper-resistant records for auditing, regulatory compliance, and long-term document storage.
• Universal sharing — Share data with stakeholders who don’t have Excel or prefer read-only formats that prevent accidental editing.
• Print-ready documents — Ensure spreadsheets print exactly as intended without pagination or formatting issues.

The Excel-to-PDF API automates this process in your workflow.

Nutrient DWS Processor API

Converting Excel-to-PDF is one of 30+ operations available through our PDF API tools. Combine Excel-to-PDF conversion with other tools for complex workflows:

• Converting various file formats and consolidating them into PDFs
• Converting Excel files and then watermarking and flattening the PDFs
• Processing multiple Excel files before merging them into a single PDF

Your account includes access to all PDF API tools.

Step 1 — Creating a free account on Nutrient DWS Processor

Go to the sign-up page(opens in a new tab) to create your free account.

After account creation, the dashboard displays your plan details.

You start with 200 credits for document processing and have access to all PDF API tools.

Step 2 — Obtaining the API key

After verifying your email, get your API key from the dashboard. Click API keys in the left menu to view your keys.

Copy the Live API key for use in the Excel-to-PDF API.

Step 3 — Setting up folders and files

Create a folder called excel_to_pdf and open it in a code editor. Create two subfolders: input_documents and processed_documents.

Copy your Excel file to the input_documents folder and rename it to document.xlsx. You can use the demo document as an example.

In the root folder, create processor.js for your code.

The folder structure:

excel_to_pdf
├── input_documents
|    └── document.xlsx
├── processed_documents
└── processor.js

Step 4 — Installing dependencies

Install the required dependencies:

• axios(opens in a new tab) — For making REST API calls.
• Form-Data(opens in a new tab) — For creating form data.

Install both packages:

npm install axios
npm install form-data

Step 5 — Writing the code

Add the following code to processor.js:

// This code requires Node.js. Do not run this code directly in a web browser.

const axios = require('axios')
const FormData = require('form-data')
const fs = require('fs')

const formData = new FormData()
formData.append('instructions', JSON.stringify({
  parts: [
    {
      file: "file"
    }
  ]
}))
formData.append('file', fs.createReadStream('input_documents/document.xlsx'))

;(async () => {
  try {
    const response = await axios.post('https://api.nutrient.io/build', formData, {
      headers: formData.getHeaders({
        'Authorization': 'Bearer YOUR_API_KEY_HERE'
      }),
      responseType: "stream"
    })

    response.data.pipe(fs.createWriteStream("processed_documents/result.pdf"))
  } catch (e) {
    const errorString = await streamToString(e.response.data)
    console.log(errorString)
  }
})()

function streamToString(stream) {
  const chunks = []
  return new Promise((resolve, reject) => {
    stream.on("data", (chunk) => chunks.push(Buffer.from(chunk)))
    stream.on("error", (err) => reject(err))
    stream.on("end", () => resolve(Buffer.concat(chunks).toString("utf8")))
  })
}

Code explanation

The form variable contains the API instructions. createReadStream reads the input Excel file. The axios.post() function makes the POST request to the Excel-to-PDF API.

The API response saves to the processed_documents folder.

Output

Execute the code:

node processor.js

After successful execution, result.pdf appears in the processed_documents folder.

Final folder structure:

excel_to_pdf
├── input_documents
|    └── document.xlsx
├── processed_documents
|    └── result.pdf
└── processor.js

Additional resources

Explore more ways to work with Nutrient API:

• Postman collection — Test API endpoints directly in Postman
• Zapier integration — Automate document workflows without code
• MCP Server — PDF automation for LLM applications
• JavaScript client — Official JavaScript/TypeScript library

Conclusion

This tutorial covered converting Excel files to PDF documents in JavaScript using the Excel-to-PDF JavaScript API.

You can integrate these functions into existing applications. The same API token enables other operations like merging documents, adding watermarks, and more. Sign up(opens in a new tab) for a free trial.

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