Printer Guide

HP LaserJet Pro M404n: Duplex Printing Setup & Troubleshooting

📅 March 15, 2026⏰ 7 min read✎ DuplexFix Team

Contents

  1. M404n Duplex Capability
  2. Enable on Windows
  3. Enable on Mac
  4. Configure via HP EWS
  5. Troubleshoot Issues
  6. FAQ

The HP LaserJet Pro M404n is designed for business and comes with automatic duplex printing built-in. Here's how to enable it on Windows and Mac, and how to fix the most common issues.

M404n Duplex Capability

The HP LaserJet Pro M404n includes an automatic duplex printing unit as standard. It supports duplex on media from 60-163 gsm, including plain, letterhead, preprinted, and bond paper. Auto-duplex speed is up to 20 ppm (half the single-side speed). The M404dn and M404dw are identical models with added networking features.

Enable Duplex on Windows (M404n)

Step 1. Install the HP Full Feature Software

Download from hp.com/support/ljm404. The full driver is required to access duplex settings. The Windows generic "Microsoft IPP Class Driver" won't show duplex options.

Step 2. Enable duplex in print dialog

  1. Press Ctrl+P from your application
  2. Click Printer Properties → Finishing tab
  3. Check Print on Both Sides
  4. Verify Flip pages up is unchecked for standard long-edge binding
  5. Click OK and Print

Step 3. Set as default (optional)

Right-click the printer → Printing preferences → Finishing tab → check Print on Both Sides → Apply. This makes duplex the default for all jobs from your user account.

Enable Duplex on Mac (M404n)

  1. System Settings → Printers & Scanners → HP LaserJet M404
  2. Options & Supplies → Options → check Duplex Unit: Installed
  3. When printing: Cmd+P → Show Details → Layout dropdown → Two-Sided: Long-Edge Binding

Configure Default Duplex via HP EWS

The HP LaserJet M404n has an Embedded Web Server (EWS) for remote management:

  1. Find the printer's IP address (print a configuration page or check the printer display)
  2. Open a browser and navigate to the IP address
  3. Go to Settings → Copy/Print → Print Settings
  4. Enable Duplex Printing and click Apply

This sets the network-level default, useful for shared office deployments where you want all users to default to duplex.

Common Duplex Problems on the M404n

"Print on Both Sides" option not available

You're likely using the Windows generic driver. Download the HP UPD (Universal Print Driver) or the model-specific driver from hp.com/support. After installing, check Device Settings in Printer Properties and set Duplex Printing Unit: Installed.

Duplex pages printing with wrong orientation

If back pages are upside-down, you selected the wrong binding edge. Switch from Long-edge to Short-edge binding. In HP driver terms: uncheck "Flip pages up" for long-edge, or check it for short-edge (landscape/notepad orientation).

Page order scrambled in duplex output

This can happen with complex PDFs. Use DuplexReady to pre-process the PDF before sending it to the M404n, ensuring correct page sequencing regardless of the PDF's internal structure.

HP LaserJet pages coming out in wrong order?

DuplexReady fixes page sequencing before you even send the job to the printer.

Try DuplexReady Free

FAQ

All three have identical duplex capabilities. The M404n has USB and Ethernet only. The M404dn adds automatic duplex in the model name (though all M404 models support duplex). The M404dw adds Wi-Fi. For duplex printing setup, the steps above apply to all three.

The M404n's auto-duplexer supports A4, Letter, Legal, Executive, and A5 paper sizes. It does not support automatic duplex on envelopes, labels, or custom sizes outside the supported range. For those, single-side printing is required.

The HP LaserJet Pro M404n prints at up to 38 ppm single-sided. In duplex mode, effective output speed drops to approximately 20 ppm (measured in sheets per minute) because each sheet takes two passes through the printer.