ESP32 HTTP GET Query Parameters Not Working

In this tutorial, you'll learn about ESP32 HTTP GET Query Parameters Not Working. We cover key concepts, practical examples, and best practices.

The Problem

ESP32 GET request with URL query parameters returns wrong data or empty response.

Quick Fix

Wrong

String url = "http://api.example.com/data?q=" + query;
HTTPClient http; http.begin(url); http.GET();

URL encoding missing. Spaces in query break the request.

Right

HTTPClient http;
http.begin("http://api.example.com/data");
http.addHeader("Accept", "application/json");
http.setURL("http://api.example.com/data?q=" + urlEncode(query));
int code = http.GET();

Status: 200
Response: {"results": [{"id": 1}]}

Prevention

URL-encode query parameters. Limit query length to 2048 chars. Handle pagination. Set Accept header. Use helper function for URL encoding.

DodaTech engineers apply these same patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro for production IoT reliability.

FAQ