Check Wi-Fi Signal Strength with wdutil

Use sudo wdutil info to see RSSI, noise, channel and other live Wi-Fi link details that the menu bar hides.

macOSWi-FiwdutilDiagnosticsMedium risk

Run `sudo wdutil info` and read the RSSI and noise values — RSSI around -50 dBm is excellent, below -70 dBm is a weak signal.

01Command

Command

$ sudo wdutil info

02What it does

Modern macOS no longer offers the option-key signal readout in the Wi-Fi menu, but wdutil still prints the raw numbers: RSSI (signal strength), noise, channel width, PHY mode (Wi-Fi 4/5/6) and the security type. Comparing RSSI with the noise floor tells you the real link quality, and a very negative RSSI explains slow transfers and dropouts. The command only reads state — it changes nothing.

03Risk

RiskMedium risk

RequirementsRequires sudo (administrator password).

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

wdutil — Wi-Fi diagnostics information (macOS man page)
SS64 · technical · 2026-09-17
Evidence: Documents `sudo wdutil info`, which prints the current Wi-Fi link details: SSID, RSSI, noise, channel, PHY mode and security type.

Last verified: 2026-09-18 · Category: Network

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