(esp 32) http.GET() is so slow

Question

I want to get data from REST API by an esp32 and turning on and off LED lights(GPIO 26 and 27).
Here is my code :

#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <WiFi.h>

const char* ssid = "ssidName";
const char* password = "password";

void setup() {
Serial.begin(115200);
pinMode(26, OUTPUT);
pinMode(27, OUTPUT);

digitalWrite(26, LOW);
digitalWrite(27, LOW);

WiFi.begin(ssid, password);

Serial.println("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED){
Serial.print(".");
}
}

void loop() {
if (WiFi.status() == WL_CONNECTED){

HTTPClient http;

http.begin("https://retoolapi.dev/XB1y0H/data"); 
int httpCode = http.GET();
   

if (httpCode > 0){
  String payload = http.getString(); 
        
  payload.replace('[', ' ');
  payload.replace(']', ' ');
  char json[500];
  payload.toCharArray(json, 500);
  StaticJsonDocument<1024> doc;
  deserializeJson(doc, json);
  String led1 = doc["rele1"];
  Serial.print("led1 :");
  Serial.println(led1);
  if(led1== "1") digitalWrite(26, HIGH);
  else digitalWrite(26, LOW);
  String led2 = doc["rele2"];
  if(led2 == "1") digitalWrite(27, HIGH);
  else digitalWrite(27, LOW);
  Serial.print("led2 :");
  Serial.println(led2);
}

http.end();  
}else{
Serial.println("Check your internet connection");
}



}

It works but the problem is , it is so slow ; http.GET() takes approximately 2 seconds to be executed and I dont know why ...
Is it because of API ? Is there any better solution ? I've heard about webSocket but I'm not sure about it . Is it good and easy to integrate ?

Answer 1

The request is slow due to the ESP32 having to create the TLS (HTTPS) connection everytime which takes up to 2 seconds.

To resolve this, you can re-use the TLS connection for future requests ("persistent HTTPS connections").

Please see below a snippet of how to re-use connections and speed up requests with ESP32, which has been copied from source

HTTPClient http;

void setup() {
    // allow reuse (if server supports it)
    http.setReuse(true);
}