"html-pdf: Failed to Load PhantomJS Module"

If you've encountered the error "html-pdf: failed to load phantomjs module. You have to set the path to the phantomjs binary using 'options.phantomPath'", you're not alone. It’s a common issue faced by developers working with the html-pdf package to convert HTML to PDF in Node.js. This problem usually boils down to the PhantomJS binary not being correctly installed or the application not being able to locate it. But don’t worry—I’ve been through this before, and I’m here to help you fix it in a straightforward way. Let’s break it down and look at what causes this issue and how you can resolve it.

What’s the Issue?

This error typically appears when PhantomJS, the headless browser used to generate PDFs in the html-pdf package, cannot be found. PhantomJS is vital for rendering the HTML and converting it to PDF. When the path to its binary is incorrect or it’s not installed, the html-pdf module can’t function properly, leading to this error.

Step-by-Step Solutions

1. Install PhantomJS Globally

The easiest fix is often making sure PhantomJS is installed globally on your machine. You can do this by running the following command:

npm install -g phantomjs-prebuilt

By installing it globally, the system will have access to the PhantomJS binary, and you can directly point to it in your code.

2. Set the Path to PhantomJS Manually

If you’ve installed PhantomJS, but the error still persists, it may be because html-pdf can’t locate the binary. You’ll need to set the path manually using the phantomPath option in your configuration. Here’s how you can do that:

const pdf = require('html-pdf');
const options = { phantomPath: '/path/to/your/phantomjs' };

pdf.create(html, options).toFile('./output.pdf', function(err, res) {
  if (err) return console.log(err);
  console.log(res); // { filename: '/path/to/output.pdf' }
});

Replace '/path/to/your/phantomjs' with the actual path to your PhantomJS binary. On many systems, the path could be something like /usr/local/bin/phantomjs.

3. Ensure Compatibility with Node.js Versions

Another issue could arise from using a version of Node.js that’s incompatible with the html-pdf or PhantomJS. Make sure you’re using a LTS (Long Term Support) version of Node.js, as older or cutting-edge versions may cause compatibility problems. Check your Node.js version by running:

node -v

If you're using a newer version like Node.js 14+, consider downgrading to Node.js 12 or earlier, as reported by some users on GitHub.

4. Switch to Puppeteer as an Alternative

Sometimes, the hassle of troubleshooting PhantomJS errors isn’t worth it, especially when alternatives like Puppeteer are more reliable and widely used for similar tasks. Puppeteer is a headless Chrome browser maintained by Google and can handle HTML to PDF conversion more efficiently.

"html-pdf: Failed to Load PhantomJS Module" – How to Fix It