How to Find Arduino's IP Address via Wi-Fi: All Working Methods for ESP8266 and ESP32

Connecting Arduino to a Wi-Fi network opens up a lot of possibilities for controlling devices over the Internet, but the problem often arises: how to find out IP address of the boardto connect to it remotely? Without this address, you won't be able to open the web interface, send an HTTP request, or configure interaction with other devices on the local network. In this article, we'll cover all the current methods for obtaining IP addresses for popular modules. ESP8266 (NodeMCU, Wemos D1) and ESP32, including methods through Serial Monitor, router settings, specialized sketches and external services.

A key feature of working with Arduino is that its IP address can change each time you connect to the network (unless your router has a static IP address). Therefore, it's important not only to know the current address but also to learn how to record it or quickly find it when it changes. We'll cover solutions for various scenarios: from simply displaying the IP address in the port monitor to automated notifications via a Telegram bot. You'll also learn the differences between local (within your network) and external (global) Arduino IP addresses and when which one is needed.

Method 1: Displaying the IP address in the Serial Monitor (the easiest method)

If your Arduino is already connected to Wi-Fi and running a sketch that supports networking, the fastest way to find out its IP is to print it to Serial MonitorThis method does not require additional tools and works for any modules based on ESP8266 or ESP32.

Add the following code to your sketch (usually placed in a function setup() after connecting to Wi-Fi):

Serial.begin(115200);
WiFi.begin("your_SSID", "your_PASSWORD");

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}

Serial.println("");
Serial.print("Connected! IP address: ");
Serial.println(WiFi.localIP());

After downloading the sketch, open Serial Monitor in the Arduino IDE (Tools → Port Monitor) and set the speed 115200 baudAfter a few seconds, you will see a line like this:

Connected! IP address: 192.168.1.105

• ✅ Pros: no need to install anything, works out of the box.
• ⚠️ Cons: Requires physical connection of Arduino to computer via USB.
• 🔄 When to use: for debugging or if the board is always connected to the PC.

Method 2: View the list of devices in the router settings

If your Arduino is already connected to Wi-Fi but you don't want to connect it to your computer, you can find its IP address through the router interface. This method is universal and works for any device on the network, including ESP8266, ESP32, and even if you don't know which sketch is loaded on the board.

Instructions for most routers:

1. Open your browser and enter your router's IP address in the address bar (usually it's 192.168.0.1 or 192.168.1.1).
2. Log in (default logins/passwords can be found on the router sticker).
3. Go to the section with a list of connected devices. The section name depends on the model:
   • TP-Link: DHCP → DHCP Client List
   • ASUS: Network Map → Clients
   • Keenetic: Devices
   • MikroTik: IP → DHCP Server → Leases

If there are many devices in the list, pay attention to MAC address Arduino - it is usually printed on the module body (for example, on NodeMCU) or you can output it to Serial Monitor team Serial.println(WiFi.macAddress());.

3. Method: Using a sketch with sending IP via UDP or HTTP

If you need to obtain the Arduino's IP address remotely (without connecting to the Serial Monitor or a router), you can program the board to automatically send its IP address to another computer on the network. This is convenient for projects where the Arduino operates autonomously, such as a weather station or a smart home system.

Below is an example sketch that sends an IP address to a computer using the protocol UDP (port 4210). Upload it to the Arduino, and on your computer, start listening to the port (for example, via netcat or Packet Sender):

#include<WiFi.h> // For ESP32 (for ESP8266 use<ESP8266WiFi.h> )
#include <WiFiUdp.h>

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
WiFiUDP udp;

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}

udp.begin(4210);
IPAddress localIP = WiFi.localIP();
char ipStr[16];
sprintf(ipStr, "%d.%d.%d.%d", localIP[0], localIP[1], localIP[2], localIP[3]);

udp.beginPacket("192.168.1.100", 4210); // Replace with your PC's IP
udp.print("Arduino IP: ");
udp.print(ipStr);
udp.endPacket();
}

void loop() {}

To listen for UDP packets on a computer (Windows), use the command:

nc -ulvp 4210

• 📡 UDP alternative: sending IP via HTTP request to a local server (e.g. http://192.168.1.100/log?ip=ARDUINO_IP).
• 🔌 For ESP8266: replace #include <WiFi.h> on #include <ESP8266WiFi.h>.
• ⚠️ Limitation: The computer must be on the same network as the Arduino.

Method 4: Arduino Web Server with IP Output

One of the most convenient methods is to run a simple web server on your Arduino, which will display its IP address when opened in a browser. This allows you to find out the IP address at any time by simply entering something like http://arduino.local (if mDNS is configured) or current IP.

Example sketch for ESP8266/ESP32 with web server:

#include<WiFi.h> // or<ESP8266WiFi.h> for ESP8266
#include <WebServer.h>

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
WebServer server(80);

void handleRoot() {
String ip = WiFi.localIP().toString();
String html = "<html><body><h1>Arduino IP</h1><p>" + ip + "</p></body></html>";
server.send(200, "text/html", html);
}

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) delay(500);

server.on("/", handleRoot);
server.begin();
}

void loop() {
server.handleClient();
}

After loading the sketch:

1. Find out the Arduino IP using any of the previous methods (for example, via Serial Monitor).
2. Enter this IP in the address bar of your browser (for example, http://192.168.1.105).
3. You will see a page with your current IP address.

Upload a sketch with WebServer support|Connect Arduino to Wi-Fi|Find out the board's IP (via Serial or router)|Open the IP in a browser|If necessary, refresh the page (F5) for the current IP-->

If you're using an ESP32 with dual Wi-Fi (2.4 GHz + 5 GHz), the web server will only be accessible through the network the board is connected to. For example, if the Arduino is connected to the 5 GHz band and your computer is connected to the 2.4 GHz band of the same router, access to the server may not work.

5. Method: Using mDNS (access by name instead of IP)

Protocol mDNS (Multicast DNS) allows you to access Arduino not by IP address, but by a friendly name, for example http://arduino.localThis eliminates the need to constantly find out the IP address, especially if it changes after rebooting the router. mDNS is supported by most modern operating systems (Windows 10+, macOS, Linux) and modules. ESP8266/ESP32.

An example sketch with mDNS support:

#include <WiFi.h>
#include<ESPmDNS.h> // For ESP32 (for ESP8266: #include<ESP8266mDNS.h> )

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) delay(500);

if (!MDNS.begin("arduino")) { // "arduino" is the hostname (will be accessible as arduino.local)
Serial.println("Error starting mDNS!");
} else {
Serial.println("mDNS is running. Open http://arduino.local");
}
}

void loop() {}

After loading the sketch:

1. Make sure your computer and Arduino are connected to the same network.
2. Open in browser http://arduino.local (or other name specified in MDNS.begin()).
3. If the page doesn't open, check mDNS support in your OS:
   • Windows: install Bonjour Print Services.
   • Linux: install the package avahi-daemon (sudo apt install avahi-daemon).
   • Android: use apps like Network Browser.

⚠️ Attention: On some corporate networks or guest Wi-Fi networks, mDNS may be blocked by the administrator. In this case, use standard IP detection methods.

6. Method: Arduino's external IP address (for remote access)

All previous methods help to find out local IP Arduino (for example, 192.168.1.105), which only works within your home network. If you need to connect to the Arduino from the internet (for example, to control a smart home remotely), you'll need external (public) IP address your router + setting up port forwarding (Port Forwarding).

How to find out your external IP:

1. Open any IP address detection service in your browser, for example:
   • ifconfig.me
   • 2ip.ru
   • whatismyipaddress.com

#include <WiFi.h>
WiFi.config(IPAddress(192, 168, 1, 105), IPAddress(192, 168, 1, 1), IPAddress(255, 255, 255, 0));

void handleRoot() {
if (!server.authenticate("admin", "your_password")) {
return server.requestAuthentication();
}
// Your code for authorized users
}