Potentially, one of the great things about having a device connected to the network is that you can update it remotely. However, how do you make that happen? If you use the Arduino setup for the ESP8266 or ESP32, you might try [scottchiefbaker’s] library which promises to make the process easy.
Adding it looks to be simple. You’ll need an include, of course. If you don’t mind using port 8080 and the path /webota, you only need to call handle_webota() from your main loop. If you want to change the defaults, you’ll need to add an extra call in your setup. You also need to set up a few global variables to specify your network parameters.
The only caveat is that long delay statements in your loop can block things from working and aren’t a great idea anyway. If you have them, you can replace all your delay calls with webota_delay which will stop the system from ignoring update requests.
The code started from a different online tutorial but packaged the code up nicely for reuse. To do an update, simply navigate to the device with a web browser and use the correct port number and path. From there you can upload a new binary image taken from the Arduino IDE with the export compiled binary command.
The only concern we saw was the code didn’t appear to authenticate you at all. That means anyone could load code into your ESP. That might be ok on a private network, but on the public Internet it is surely asking for trouble. The original tutorial code did have a hardcoded user and password, but it didn’t look very useful as the password was in the clear and didn’t stop you from uploading if you knew the right URL. Dropping it from the library probably makes sense, but we would want to build some kind of meaningful security into anything we deployed.
If you have a network connection, we’ve seen the same trick done with a normal Arduino with a wireless chip. You can even do it over WiFi but using an ESP8266 which you’ll then want to be able to update, too.
Source: LIBRARY MAKES ESP OVER THE AIR UPDATES EASY
French 
English