How Do I Transfer Data From NodeMCU to Web Server?


Heather Bennett

How Do I Transfer Data From NodeMCU to Web Server?

NodeMCU is a widely used development board based on the ESP8266 Wi-Fi module. It enables you to easily connect your projects to the internet and communicate with web servers.

In this tutorial, we will learn how to transfer data from a NodeMCU board to a web server using the HTTP protocol.


Before we begin, make sure you have the following:

  • A NodeMCU board
  • An active Wi-Fi connection
  • A web server with an API endpoint to receive data
  • An Arduino IDE installed on your computer
  • The ESP8266 library installed in your Arduino IDE

Step 1: Setting Up the NodeMCU Board

To start, connect your NodeMCU board to your computer using a USB cable. Open the Arduino IDE and go to “File” > “Examples” > “ESP8266” > “WiFiClient” and open the “WiFiClientBasic” sketch.

Now, replace the placeholders in the code with your Wi-Fi credentials. Update the following lines:

const char* ssid = "YourWiFiSSID";
const char* password = "YourWiFiPassword";
const char* host = "YourWebServerIPAddress";
const int port = YourWebServerPort;

Save and upload the sketch to your NodeMCU board by clicking on the upload button (right arrow) in the Arduino IDE.

Step 2: Sending Data to the Web Server

In this step, we will modify the previous sketch to send data to the web server. Add the following code after the line client.println("Connection: close");:

client.println("Content-Type: application/x-www-form-urlencoded");
client.print("Content-Length: ");

Replace data with the actual data you want to send to the web server. It could be sensor readings, status updates, or any other information you want to transmit.

Save and upload the modified sketch to your NodeMCU board.

Step 3: Receiving Data on the Web Server

On your web server, create an API endpoint that can receive and process data sent by the NodeMCU board. You can use any programming language or framework of your choice for this task.

In this example, we will use PHP to create a simple API endpoint. Create a new PHP file and add the following code:

$data = $_POST['data'];
// Process received data here

Save the PHP file on your web server and note down its URL or IP address.

Step 4: Testing the Data Transfer

To test if everything is working correctly, open the Serial Monitor in the Arduino IDE (baud rate set to 115200). You should see “Connected” indicating that your NodeMCU board has successfully connected to your Wi-Fi network.

Next, check if there are any errors in establishing a connection with your web server. If successful, you will see “Connected to Web Server” in the Serial Monitor.

Finally, verify if the data is being sent to the web server. On the Serial Monitor, you should see “Data Sent” indicating that the data has been successfully transmitted to your web server.


In this tutorial, we have learned how to transfer data from a NodeMCU board to a web server using the HTTP protocol. We covered the steps required to set up the NodeMCU board, send data to the web server, receive and process that data on the server side.

By following this guide, you can establish communication between your IoT projects and a remote web server, enabling real-time monitoring and control over the internet.

Experiment with different types of data and explore further possibilities by integrating other sensors or actuators with your NodeMCU board. The possibilities are endless!

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