Comment by ustad

2 days ago

But the browser is involved. Can the browser do OTA to esp32?

The browser connects to a webserver running on the ESP32. Over wifi -> over the air. OTA doesn't mean headless or automatic

I believe the ESP32 runs a small web server that supports WebSerial (?), if you can reach it over WiFi or somesuch, you should be able to upload the new firmware blob that way.