Comments on: ESP32 HTTP GET and HTTP POST with Arduino IDE (JSON, URL Encoded, Text)

By: Peter

Peter — Mon, 28 Jul 2025 16:45:35 +0000

for newest library this line of code is obselute:
http.begin(serverPath.c_str());
so i used:
http.begin(wifiClient, serverPath); // Initialize with full URL
where serverpath is http://192.168.1.107/get-esp-data.php?apikey….
i also used some debug lines in code bellow which helped for solving the -1,404 code.
Lot of issues in php code, xampp server , code in arduino from my changes. One more problem is that you need to be connected to the same wifi network ( xampp, lampp + esp).
i did used another way of a code but maybe it helps somebody.
void upload() {
if (WiFi.status() != WL_CONNECTED) {
Serial.println(“WiFi Disconnected”);
return;
}
//ip address of a server
Serial.println(“Connecting to: ” + String(serverName));
//ip adress of a esp
Serial.println(“STA IP: ” + WiFi.localIP().toString());

// Create the server path
String serverPath = String(“http://”) + serverName +
“?api_key=” + apiKeyValue +
“&data=” + data +
“&data2=” + data2 +
“&teplota=” + temp;

HTTPClient http;

int httpResponseCode = http.GET();
Serial.println(“HTTP Response code: ” + String(httpResponseCode));

if (httpResponseCode > 0) {
String payload = http.getString();
Serial.println(“Payload: ” + payload);
} else {
Serial.println(“Error: ” + http.errorToString(httpResponseCode));
}

http.end(); // Free resources
}

firstly use get method for test and then go to post. It will help you. Also some easy code from start – test it step by step. othervise you will be lost – as me 🙂

great tutorial. Helped me 2-3 years ago. Helped me now

By: Peter

Peter — Mon, 28 Jul 2025 16:35:05 +0000

In reply to Uziel. there could be a very wide range of a issues. ai helped me. generally you need to check everything.

By: Sara Santos

Sara Santos — Fri, 25 Jul 2025 16:11:44 +0000

In reply to R Wells.

Hi.
After opening the Serial Monitor, press the ESP32 RST button. This way, you can catch what is prints at setup().
Regards,
Sara

By: R Wells

R Wells — Wed, 23 Jul 2025 17:57:59 +0000

Thank you for this tutorial. I looked about quite a bit for a tutorial explaining what turned out to be the Post request. I’m sure I would have found more if I had known the terms to search for but your tutorial showed me what I needed.

On thing I don’t understand though. None of the Serial Print commands work for me except for the HTTP Response section. None of the Serial Print commands in the Setup section print anything in the Serial Monitor, nor does any I add to the Loop section.

Any idea what that is?

By: dekip

dekip — Sun, 18 May 2025 06:47:39 +0000

Just to add that after V3.x.x, every GET request returns -1 error HTTP code. Is there any fix for this?

By: Uziel

Uziel — Wed, 19 Mar 2025 16:32:37 +0000

I have tried a variety of codes, been trying to GET/POST from my esp32 to my local Django REST API, but the esp32 just keeps giving me error code -1. 🙁

By: Jean-roch Blais

Jean-roch Blais — Sat, 07 Sep 2024 20:04:45 +0000

Sorry for posting this about a day or two:

“this code does not work ” … (It works, my bad …)

// Your Domain name with URL path or IP address with path
http.begin(serverPath.c_str());

// If you need Node-RED/server authentication, insert user and password below //http.setAuthorization("REPLACE_WITH_SERVER_USERNAME", "REPLACE_WITH_SERVER_PASSWORD");

// Send HTTP GET request int httpResponseCode = http.GET();

jrb.

By: Talha

Talha — Thu, 04 Jul 2024 09:11:30 +0000

Hello!

I am sending the data to server using the following function, the problem is when the data from the sensors is small, it works fine and send all data to server like for one hour of data.
But when I increase the data size it does not send the data and doesn’t give any responsecode.
Can somebody assist?

void sendDataToServer(const String & payload) {
// Print the payload for debugging
Serial.println(“Payload to be sent to server:”);
Serial.println(payload);
HTTPClient http;
http.begin(serverName);
http.addHeader(“Content-Type”, “application/json”);

int httpResponseCode = http.POST(payload);

esp_task_wdt_reset(); // Reset the watchdog timer

if (httpResponseCode > 0) {
Serial.print(“HTTP Response code: “);
Serial.println(httpResponseCode);

String response = http.getString(); Serial.println(response);

} else {
Serial.print(“Error code: “);
Serial.println(httpResponseCode);
}

http.end();
}

By: Talha

Talha — Thu, 04 Jul 2024 09:05:54 +0000

In reply to G Reddy.

Hello
Have you find an answer to this? I’m also getting this -11 response although the server is okay?
And it occurs when I send large data file, on small data it works fine. why is it so?

By: Sara Santos

Sara Santos — Wed, 17 Apr 2024 22:09:48 +0000

In reply to John Pool.

Hi.
That’s great.
Thanks for sharing.
Regards,
Sara