Introduction

Updating firmware on an ESP32 using a USB cable every time can be frustrating—especially once the device is installed inside an enclosure or deployed remotely.
That’s where OTA (Over-The-Air) updates for ESP32 OTA come in.

Firmware updates are crucial for maintaining the security and functionality of your devices. Regular updates can patch vulnerabilities and introduce new features, making OTA updates an essential practice for IoT developers.

This method not only enhances convenience but also significantly reduces downtime and manual intervention, especially beneficial for devices deployed in hard-to-reach locations.

In this blog, you’ll learn how to use OTA with ESP32 using the ElegantOTA library, which provides a clean web-based interface to update firmware wirelessly for ESP32 OTA. No command line, no extra tools—just upload your .bin file from a browser.

OTA updates are used widely in various consumer electronics, from smartphones to smart home devices, illustrating their versatility and effectiveness in modern technology.

What is OTA (Over-The-Air) Update?

OTA (Over-The-Air) update allows you to:

• Upload new firmware wirelessly
• Avoid physical USB connections
• Update devices remotely via Wi-Fi
• Save time during development and deployment

ESP32 fully supports OTA, and ElegantOTA makes it extremely easy.

What is ElegantOTA Library?

ElegantOTA is a lightweight Arduino library that adds a beautiful web UI to your ESP32 for firmware updates.

The ElegantOTA library stands out because it simplifies the OTA process significantly. Users can focus on their core application, knowing that firmware updates are handled seamlessly through an intuitive interface.

Key Features of ElegantOTA

• Web-based OTA interface
• Supports ESP32 and ESP8266
• Simple integration with Arduino IDE
• Password protection supported
• No external tools required

Moreover, the library ensures that updates are performed securely, reducing the risk of unauthorized access during the firmware update process.

Requirements

Before starting, make sure you have:

• ESP32 development board
• Arduino IDE (latest version)
• ESP32 Board Package installed
• Wi-Fi network
• USB cable (for first upload)

Installing ElegantOTA Library

Additionally, ElegantOTA supports various authentication methods, providing enhanced security measures that are critical in IoT applications.

Step 1: Install Required Libraries

Open Arduino IDE → Library Manager → install:

• AsyncElegantOTA
• ESPAsyncWebServer
• AsyncTCP
• ElegantOTA

⚠️ Note: ElegantOTA works best with Async Web Server, not the default WebServer.

ESP32 OTA Code Using ElegantOTA

Here’s a basic working example:

Once the library is installed, users will be amazed by how quickly they can deploy updates without the need for intricate coding or extensive setup processes.

To ensure the best performance, it is advisable to use the latest versions of the required libraries to leverage improvements and bug fixes made by the community.

#include <Arduino.h>
#include <WiFi.h>
#include <WebServer.h>
#include <ElegantOTA.h>

const char* ssid = "Airtel_Akash";
const char* password = "9598877888";

WebServer server(80);

void setup() {
  Serial.begin(115200);

  WiFi.begin(ssid, password);
  Serial.print("Connecting");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nConnected!");
  Serial.println(WiFi.localIP());

  server.on("/", HTTP_GET, []() {
    server.send(200, "text/plain", "ESP32 OTA Ready");
  });

  ElegantOTA.begin(&server);  // ✅ Correct server type
  server.begin();

  Serial.println("HTTP server started");
}

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





// http://192.168.1.11/update

// EXPORT TO BINARY Then Upload

#include <Arduino.h>
#include <WiFi.h>
#include <WebServer.h>
#include <ElegantOTA.h>

const char* ssid = "Airtel_Akash";
const char* password = "9598877888";

WebServer server(80);

void setup() {
  Serial.begin(115200);

  WiFi.begin(ssid, password);
  Serial.print("Connecting");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("\nConnected!");
  Serial.println(WiFi.localIP());

  server.on("/", HTTP_GET, []() {
    server.send(200, "text/plain", "ESP32 OTA Ready");
  });

  ElegantOTA.begin(&server);  // ✅ Correct server type
  server.begin();

  Serial.println("HTTP server started");
}

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





// http://192.168.1.11/update

// EXPORT TO BINARY Then Upload

This example demonstrates the basic functionality of the ElegantOTA library, but the possibilities extend far beyond, allowing for custom update notifications and error handling mechanisms to enhance user experience.

For more advanced users, integrating additional features such as logging and analytics can provide insights into the update process, making future updates even smoother.

Moreover, testing the update process in a development environment before deploying to production can prevent potential pitfalls and ensure a seamless upgrade experience for end-users.

In conclusion, leveraging the ElegantOTA library for ESP32 OTA updates not only simplifies the process but also enhances the reliability and security of firmware updates.

As IoT continues to grow, mastering OTA techniques will be vital for anyone looking to keep their devices updated and secure.

How to Upload Firmware Using ElegantOTA

1. Upload the above code once via USB
2. Open Serial Monitor
3. Copy the ESP32 IP Address
4. Open browser → http://ESP32_IP/update
5. Upload the new firmware .bin file
6. Click Update
7. ESP32 reboots automatically 🚀

How to Get .bin File from Arduino IDE

• Click Sketch → Export Compiled Binary
• .bin file will be generated in sketch folder
• Use this file for OTA updates

Advantages of Using ElegantOTA

• No need for USB after first upload
• Fast and reliable updates
• Ideal for IoT and production devices
• Clean UI for non-technical users
• Works over local network

Common Errors & Fixes

ElegantOTA Not Opening

• Ensure ESP32 and PC are on same Wi-Fi
• Check IP address from Serial Monitor

Compilation Error

• Install AsyncTCP and ESPAsyncWebServer
• Avoid mixing WebServer.h with async server

OTA Fails Mid-Upload

• Use stable Wi-Fi
• Avoid large firmware size
• Disable firewall temporarily

Is ElegantOTA Secure?

Yes, ElegantOTA supports:

• Username & password protection
• Can be combined with HTTPS (advanced use)

For production devices, always enable authentication.

Use Cases of ESP32 OTA

• IoT devices
• Smart home products
• Wearables
• Security devices
• Remote monitoring systems
• Startup hardware products

FAQ – ESP32 ElegantOTA

Q1. Is ElegantOTA free?

Yes, it is open-source and free to use.

Q2. Does ElegantOTA support ESP8266?

Yes, both ESP32 and ESP8266 are supported.

Q3. Can I update ESP32 from mobile?

Yes, OTA page works on mobile browsers too.

Q4. Is internet required for OTA?

No, only local Wi-Fi network is required.

Conclusion

Using ElegantOTA with ESP32 is one of the easiest and most professional ways to handle firmware updates wirelessly. Whether you’re building a prototype or deploying hundreds of devices, OTA saves time and effort.

If you’re working on IoT or smart hardware projects, ElegantOTA is a must-have tool in your ESP32 workflow.