Why won't Lùmen connect to my laser over WiFi?

Work through four checks: the machine must have a WiFi-capable controller (ESP32/ESP3D-class — classic USB-only GRBL boards have no WiFi), your Mac and the engraver must be on the same network (or your Mac joined to the machine's own hotspot), the IP address and port must be right (most controllers use TCP port 23, and the IP can change after a router reboot), and Lùmen must have the macOS Local Network permission (System Settings → Privacy & Security → Local Network).

Does my laser engraver support WiFi?

Only machines with an ESP32/ESP3D-class controller and network firmware — such as the Algolaser Pixie — expose GRBL over WiFi (a raw TCP connection, typically on port 23). Classic USB-only GRBL boards with a CH340/CP210x serial chip have no radio, and no adapter or dongle can add WiFi to them. If your machine is USB-only, connect via USB instead.

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I can't connect to my laser over WiFi

Connection & setup · Updated: July 21, 2026

WiFi in Lùmen is GRBL over TCP: the same command stream as USB, sent over the network to the controller's IP address and port. When Connect fails or times out, one of four things is almost always wrong. Work through them in order.

1. Check that your machine actually supports WiFi

Only machines with an ESP32/ESP3D-class controller and network firmware — the Algolaser Pixie is a typical example — expose GRBL over WiFi. Classic USB-only GRBL boards (the ones with a CH340 or CP210x serial chip) have no radio at all: no adapter or dongle can add WiFi to them. If your machine is USB-only, that's not a bug — connect via USB instead.

Not sure which kind you have? The WiFi laser engraver guide explains how to tell, and how the whole setup works.

2. Get Mac and machine on the same network

Your Mac must be able to reach the controller's IP address:

Same WiFi network — the usual setup: both the engraver and your Mac joined to your home/workshop network.
Machine hotspot — some controllers broadcast their own access point (e.g. ALA1-AP-xxxx). Join it from your Mac's WiFi menu. Note that while connected to the hotspot, your Mac usually has no internet.

3. Verify the IP address and port

Most ESP32/ESP3D laser controllers expose the GRBL stream on TCP port 23 (some firmware uses a different one — check your machine's documentation). The IP address is shown by the machine's own app/display, or can be read over USB with the $WRS command in the console.

Keep in mind the IP can change after a router reboot (DHCP). If a connection that used to work suddenly doesn't, re-check the IP first — and consider giving the engraver a reserved/static IP in your router settings so it stops moving.

4. Allow the macOS Local Network permission

The first time an app connects to a device on your local network, macOS shows a “Local Network” permission prompt. If it was denied (or dismissed), connections to 192.168.x.x addresses fail or hang. Fix it in System Settings → Privacy & Security → Local Network: make sure Lùmen is enabled, then try again.

Still failing? Two more things to try

Power-cycle the engraver. ESP32 controllers occasionally stop accepting connections until rebooted.
Close other software. Most of these controllers accept only one TCP client at a time — a leftover LightBurn session or an open Telnet window can hold the slot.

If the connection drops mid-job

WiFi can drop silently where USB would fail loudly — weak signal, router restarts, controller reboots. Lùmen's stall watchdog warns you when a running job goes quiet. After any disconnect, reconnect and home the machine again before restarting the job: the controller loses its position state. For long jobs, prefer a strong signal or the USB cable, and see the WiFi guide for the reliable-streaming mode.

Still stuck?

Reach out to support with your engraver model and controller/firmware, the IP and port you're using, and how the machine is on the network (home WiFi or hotspot) — that's usually enough to pin it down quickly.