Scanning

Share a USB scanner with NAPS2

Use a free NAPS2 scanner-sharing server on a Mac or Windows PC to make a USB, TWAIN, WIA, SANE, or otherwise non-AirScan scanner appear to PDFScanner Neo as a network scanner.

When this helps

PDFScanner Neo scans from AirScan/eSCL devices on your local network. If your scanner only connects by USB, or if it needs a Mac or Windows driver, it normally will not appear in Neo. NAPS2 can bridge that gap: the computer that can already use the scanner shares it over the standard eSCL protocol, and Neo discovers it like any other AirScan scanner.

NAPS2 is free, with no ads or restrictions. It only has to run on the computer connected to the scanner; you do not install anything on the iPhone or iPad.

Set up the scanner on the computer

1. Install NAPS2. Download it from naps2.com on the Mac or Windows computer that is connected to the scanner.

2. Make sure NAPS2 can scan locally. Create or select a NAPS2 scan profile for the attached scanner and run a quick test scan. Use whatever driver works for that scanner on the computer, such as TWAIN, WIA, Apple Image Capture, or SANE.

3. Open Scanner Sharing. In NAPS2, open the Scanner Sharing window from the Profiles window or the Scan dropdown.

4. Click Share. Choose the scanning device you want to publish. Give it a clear name, for example Office USB Scanner; this is the name Neo will show.

5. Leave NAPS2 running. Shared scanners are available only while NAPS2 is open on that computer.

Scan from PDFScanner Neo

1. Connect the iPhone or iPad to the same Wi-Fi or local network as the computer running NAPS2.

2. Open PDFScanner Neo and allow Local Network access if iOS asks.

3. Open the scanner picker at the top of the scan panel and tap Refresh scanners if needed.

4. Select the NAPS2-shared scanner by the name you chose, then scan normally. Pages arrive in the Neo workspace, where you can clean up, OCR, organize, and save them like any other hardware scan.

If the scanner does not appear

• Keep NAPS2 open. NAPS2 scanner sharing is not currently a background service; closing the app stops sharing.
• Check the network. The iPhone/iPad and computer should usually be on the same subnet. Guest Wi-Fi, VPNs, and client isolation often block discovery.
• Allow discovery traffic. eSCL discovery uses mDNS multicast on UDP 5353. Firewalls also need to allow direct connections from the iPhone/iPad to the computer.
• Allow NAPS2 ports. NAPS2 uses TCP ports 9801-9850 for HTTP and 9901-9950 for HTTPS, assigning ports to shared devices.
• Wake the computer and scanner. Sleep mode can make the shared scanner disappear until the computer or scanner is awake again.

Privacy and trust

The scan data travels on your local network between the iPhone/iPad and the computer running NAPS2, then from that computer to the scanner. NAPS2 uses HTTPS by default with a self-signed certificate and can fall back to HTTP if needed. Use this on networks you trust, and remove the shared scanner in NAPS2 when you no longer need it.

Technical reference: NAPS2 Scanner Sharing documentation.