ESP32 Wi-Fi Scan Returns No Networks

In this tutorial, you'll learn about ESP32 Wi. We cover key concepts, practical examples, and best practices.

The Problem

ESP32 scans for Wi-Fi networks but returns 0 results or misses nearby access points.

Quick Fix

Wrong

int n = WiFi.scanNetworks();
if (n == 0) Serial.println("No networks found");

No networks found
(But your phone shows 5 networks in the same location.)

Right

WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
int n = WiFi.scanNetworks();
Serial.printf("Found %d networks
", n);
for (int i = 0; i < n; i++) {
  Serial.printf("%s (%d dBm) %s
",
    WiFi.SSID(i).c_str(), WiFi.RSSI(i),
    WiFi.encryptionType(i) == WIFI_AUTH_OPEN ? "OPEN" : "SECURE");
}

Found 7 networks:
MyNetwork (-42 dBm) SECURE
GuestNet (-58 dBm) OPEN
Office_5G (-63 dBm) SECURE

Prevention

Call WiFi.mode(WIFI_STA) and WiFi.disconnect() before scanning. Set scan time with WiFi.scanNetworks(true) for async mode. Parse encryption types to identify open networks. Run scans in a loop for fresh results. Remember ESP32 only detects 2.4 GHz networks.

DodaTech engineers apply these same patterns when building Doda Browser's networking stack, DodaZIP's firmware packaging pipeline, and Durga Antivirus Pro's sensor communication layer.

FAQ