Use Chrome or Edge (Web Serial required). Safari currently does not support Web Serial.
1. Connect Device
Select your RP2040 device via serial port
No device selected
2. Start Bootloader
Reboot device into BOOTSEL mode
Serial port will disappear when successful.
Status: Waiting for device
connection...
3. Confirm/Pick Drive
After reboot, device appears as RPI-RP2 drive
No drive selected
Status: Waiting for reboot...
4. Upload Firmware
Select and upload UF2 firmware file, either local or from a URL
No file selected
...OR...
Not ready
Status: Waiting for drive
selection...