# ESP32 will not connect to Wi-Fi: checks in order

> Fix an ESP32 that stays disconnected from Wi-Fi: 2.4 GHz only, SSID and password, station mode, signal and router settings.

Canonical: https://roboticsengineering.in/fix/esp32-wifi-wont-connect/ | Published: 2026-11-03 | Updated: 2026-11-04

**If WiFi.status() never reaches WL_CONNECTED, check the band and the credentials before the code.** The ESP32 joins 2.4 GHz networks only, and a typo in the name or password gives no useful error.

## What the message means

WiFi.begin() starts the connection and returns immediately. The board keeps trying in the background. Status stays at WL_DISCONNECTED or WL_NO_SSID_AVAIL until the join succeeds or fails.

## Fix it in this order

1. Confirm the router broadcasts a 2.4 GHz network. A 5 GHz-only SSID cannot be joined.
2. Check the SSID and password for case, spaces and look-alike characters. Print them to the serial monitor.
3. Call WiFi.mode(WIFI_STA) before WiFi.begin() so the board acts as a client.
4. Print WiFi.status() in a loop with a short delay and a time-out, instead of waiting forever.
5. Move the board closer to the router. A weak signal fails the handshake.
6. Try a phone hotspot on 2.4 GHz. If that works, the problem is a router setting such as WPA3-only mode or MAC filtering.
7. Check the supply. A weak USB port can reset the board during the radio start-up.

## Why it happens

The usual causes are a wrong network name or password, a router that only offers 5 GHz (the classic ESP32 supports 2.4 GHz only), a weak signal, or code that never waits for the connection. Printing the connection status shows which one you have.

```
#include <WiFi.h>
WiFi.mode(WIFI_STA);
WiFi.begin(SSID, PASS);
unsigned long t0 = millis();
while (WiFi.status() != WL_CONNECTED && millis() - t0 < 15000) { delay(250); Serial.print("."); }
Serial.println(WiFi.status() == WL_CONNECTED ? WiFi.localIP().toString() : "failed");
```

Example sketch: change pins and values for your own wiring. It has not been bench-tested on your hardware.

Check the name and password for case and hidden spaces, move closer to the router, and try a phone hotspot set to 2.4 GHz to separate a router setting from a board fault.

## If you see this, do this

| You see | Do this |
| --- | --- |
| Status is WL_NO_SSID_AVAIL | The network name is not seen. Band, spelling or range. |
| Status is WL_CONNECT_FAILED | Wrong password or a router security mode the board does not accept. |
| It connects, then drops | Weak signal or a weak supply. |

## Related

[ESP32 brownout](https://roboticsengineering.in/fix/esp32-brownout-detector-was-triggered/), [ESP32 pinout for robotics](https://roboticsengineering.in/esp32-pinout-for-robotics/), [MQTT on the ESP32](https://roboticsengineering.in/mqtt-esp32-robot-telemetry/).

Last reviewed: November 2026. These are the usual causes and the order that finds them fastest. Test on your own board; clones and cables differ.

## Why this happens

Connecting involves several steps in sequence: scan for the network, authenticate with the router, then request an IP address through DHCP. WiFi.begin() only starts this process. Each failure point gives a different status code, which is why printing the status number beats guessing. In the Arduino core 0 is idle, 1 is no SSID available, 3 is connected, 4 is connect failed and 6 is disconnected.

The classic ESP32 radio supports 2.4 GHz only. A router that merges 2.4 and 5 GHz under one name usually works because the board finds the 2.4 GHz side, but a 5 GHz-only name is invisible to it. Signal strength also decides whether the authentication exchange finishes, which is why a board that works beside the router fails across the house.

## How to confirm the cause

- Run a scan and print the list. If your network name does not appear, the board cannot see it: wrong band, range, or a hidden name.
- Look at each network’s RSSI in the scan. Values around minus 70 dBm or weaker are marginal for a reliable join.
- Print WiFi.status() each second for about 15 seconds. The final number tells you whether the problem is finding the network or joining it.
- Try a phone hotspot set to 2.4 GHz with a simple name and password. If it works, the problem is the router.
- Check the router for WPA3-only mode, MAC filtering or a limit on connected devices.

## Worked example

This scan sketch lists every network the board can hear with its channel and signal strength.

```
#include <WiFi.h>
void setup() {
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  WiFi.disconnect();
  int n = WiFi.scanNetworks();
  for (int i = 0; i < n; i++)
    Serial.printf("%d: %s ch%d %ddBm\n", i, WiFi.SSID(i).c_str(), WiFi.channel(i), WiFi.RSSI(i));
}
void loop() {}
```

If your network is listed with a reasonable signal, the problem is the password or the security mode. If it is missing, work on band, range and name.

## Common mistakes

- Calling WiFi.begin() again and again inside loop(), which restarts the attempt each time.
- Typing the name with a different capital letter or a trailing space.
- Using a phone hotspot that is set to 5 GHz only.
- Waiting only a second or two before deciding it failed; joining often takes several seconds.

## If this did not fix it

- Weak power: a poor USB port can reset the board when the radio starts.
- Hidden network name: a hidden name needs the correct name in code and may need a scan first.
- Router with a small DHCP pool or a client limit: the join works but no address is given.