Native Backend Troubleshooting

This guide helps diagnose and resolve issues with the native PDFium backend in Node.js.

Native Backend Not Loading

Symptoms

const pdfium = await PDFium.init({ useNative: true });
// Returns PDFium (WASM) instead of NativePDFiumInstance

Diagnosis Steps

1. Check if native is available:

import { PDFium, NativePDFiumInstance } from '@scaryterry/pdfium';

const pdfium = await PDFium.init({ useNative: true });
console.log('Backend:', pdfium instanceof NativePDFiumInstance ? 'Native' : 'WASM');

2. Check native directly:

const native = await PDFium.initNative();
if (!native) {
  console.log('Native backend unavailable');
} else {
  console.log('Native backend available');
  native.dispose();
}

3. Check installed packages:

pnpm list | grep pdfium

Common Causes

Platform Package Not Installed

The native backend requires a platform-specific package:

Platform	Package
macOS Apple Silicon	@scaryterry/pdfium-darwin-arm64
macOS Intel	@scaryterry/pdfium-darwin-x64
Linux x64 (glibc)	@scaryterry/pdfium-linux-x64-gnu
Linux ARM64 (glibc)	@scaryterry/pdfium-linux-arm64-gnu
Windows x64	@scaryterry/pdfium-win32-x64-msvc

Solution: Install the correct package:

# Check your platform
node -e "console.log(process.platform, process.arch)"

# Install appropriate package
pnpm add @scaryterry/pdfium-darwin-arm64  # macOS Apple Silicon
pnpm add @scaryterry/pdfium-linux-x64-gnu # Linux x64

Architecture Mismatch

The installed package must match your CPU architecture.

Common mistake: Installing x64 package on ARM64 (Apple Silicon, AWS Graviton).

Solution:

# Check your architecture
node -e "console.log(process.arch)"

# Reinstall correct package
pnpm remove @scaryterry/pdfium-darwin-x64
pnpm add @scaryterry/pdfium-darwin-arm64

glibc vs musl (Alpine Linux)

The Linux packages are built against glibc. Alpine Linux uses musl libc.

Symptom: Error: Error loading shared library or GLIBC_X.XX not found

Solutions:

1. Use a glibc-based image (Debian, Ubuntu):

# Instead of alpine
FROM node:22-slim

2. Or use the WASM backend (recommended for containers):

// Don't request native in Alpine
using pdfium = await PDFium.init();

Library Loading Errors

macOS Code Signing

Symptom: code signature invalid or not valid for use in process

This can occur if the binary is modified or if Gatekeeper blocks it.

Solutions:

1. Re-sign the binary:

codesign --force --sign - node_modules/@scaryterry/pdfium-darwin-arm64/*.node

2. Clear quarantine:

xattr -d com.apple.quarantine node_modules/@scaryterry/pdfium-darwin-arm64/*.node

Linux Missing Dependencies

Symptom: error while loading shared libraries

The native binary may require system libraries.

Solution: Install required packages:

# Debian/Ubuntu
apt-get install libc6 libstdc++6

# RHEL/CentOS
yum install glibc libstdc++

Windows Visual C++ Runtime

Symptom: The specified module could not be found or VCRUNTIME140.dll

Solution: Install Visual C++ Redistributable:

Download from Microsoft

Performance Issues

Verifying Native is Active

import { PDFium, NativePDFiumInstance } from '@scaryterry/pdfium';

const pdfium = await PDFium.init({ useNative: true });

if (pdfium instanceof NativePDFiumInstance) {
  console.log('✓ Using native backend');
} else {
  console.log('✗ Fell back to WASM - check platform package installation');
}

Benchmark Comparison

import { PDFium, NativePDFiumInstance } from '@scaryterry/pdfium';

async function benchmark() {
  const data = await fs.readFile('test.pdf');

  // WASM
  const wasmPdfium = await PDFium.init({ forceWasm: true });
  const wasmStart = performance.now();
  const wasmDoc = await wasmPdfium.openDocument(data);
  const wasmPage = wasmDoc.getPage(0);
  wasmPage.render({ scale: 2 });
  const wasmTime = performance.now() - wasmStart;
  wasmPage.dispose();
  wasmDoc.dispose();
  wasmPdfium.dispose();

  // Native
  const nativePdfium = await PDFium.init({ useNative: true });
  if (nativePdfium instanceof NativePDFiumInstance) {
    const nativeStart = performance.now();
    const nativeDoc = nativePdfium.openDocument(data);
    const nativePage = nativeDoc.getPage(0);
    nativePage.render({ scale: 2 });
    const nativeTime = performance.now() - nativeStart;
    nativePage.dispose();
    nativeDoc.dispose();
    nativePdfium.dispose();

    console.log(`WASM: ${wasmTime.toFixed(2)}ms`);
    console.log(`Native: ${nativeTime.toFixed(2)}ms`);
    console.log(`Speedup: ${(wasmTime / nativeTime).toFixed(2)}x`);
  }
}

Docker and Containers

glibc vs Alpine

# RECOMMENDED: Use glibc-based image
FROM node:22-slim

# NOT RECOMMENDED: Alpine uses musl
# FROM node:22-alpine

Multi-platform Builds

For multi-architecture Docker images:

FROM node:22-slim

# Install platform package based on architecture
RUN case "$(uname -m)" in \
      x86_64) pnpm add @scaryterry/pdfium-linux-x64-gnu ;; \
      aarch64) pnpm add @scaryterry/pdfium-linux-arm64-gnu ;; \
    esac

Or use buildx with platform-specific builds:

docker-compose.yml

services:
  app:
    build:
      context: .
      platforms:
        - linux/amd64
        - linux/arm64

Container Best Practice

For containers, consider always using WASM for simplicity:

// Simpler container deployment
using pdfium = await PDFium.init({ forceWasm: true });

This eliminates platform package complexity and works identically across all containers.

Fallback Behaviour

The library handles native unavailability gracefully:

// useNative: true falls back to WASM if native unavailable
const pdfium = await PDFium.init({ useNative: true });
// Always returns a working instance (native or WASM)

To require native and fail if unavailable:

const native = await PDFium.initNative();
if (!native) {
  throw new Error('Native backend required but unavailable');
}

Reporting Issues

If you encounter native backend issues, include:

1. Platform info:

node -e "console.log({ platform: process.platform, arch: process.arch, version: process.version })"

2. Installed packages:

pnpm list | grep pdfium

3. Error message (full stack trace)

4. Minimal reproduction if possible

Open issues at: https://github.com/jacquesg/pdfium/issues

See Also

• Native vs WASM Backends — Backend comparison
• Installation Guide — Setup instructions
• Performance Guide — Optimisation tips