By default, the Arduino IDE does not save a HEX file in your project folder. You must manually export it or find it in temporary system folders. Method 1: Export Compiled Binary (Recommended)
You will likely see two versions. For standard flashing, use the one without "with_bootloader" in the name. Method 2: Finding the Temporary Build Folder arduino uno hex file download
Go to > Show Sketch Folder . You will now see your .hex files there. By default, the Arduino IDE does not save
In the bottom output window, scroll to find a file path ending in .hex . It will look something like C:\Users\Name\AppData\Local\Temp\arduino_build_xxxxxx/sketchname.ino.hex . How to Upload (Flash) a HEX File to Arduino UNO arduino uno hex file download