ESP‑S3‑KEY·BADUSB WebFlasher

No device

Step 01 of 04

Read this first.

This writes the ESP32-S3 Key BadUSB firmware onto the device over USB. It replaces whatever firmware is on it now.

Flashing overwrites the app partition. Your SD-card payloads and files are not touched, but the firmware is. Only run this on your own device.

Step 02 of 04

Download mode.

The ESP32-S3 flashes over its own USB. Most units drop into download mode on their own when the flasher connects. If yours does not, hold BOOT while plugging it in, then let go.

Chrome or Edge only — Firefox and Safari have no WebSerial.

Step 03 of 04

Connect.

Pick the device in the browser prompt. It appears under vendor 303A (Espressif) as a USB serial port.

Step 04 of 04

Flash.

Erase, then write each image at its offset, then reboot. Do not unplug until the log says it is done.

0 / 0 KB 0 / 0 parts ready

Image: latest release
Chip: ESP32-S3

Choose file

Flash multiple devices — re-arm for the next unit after each success Fully erase flash before writing — wipes NVS & saved WiFi/settings

Complete

Flashed.

The device has been reset and is running the new firmware. It will re-enumerate — as a keyboard, a serial port, or its Wi-Fi AP, depending on how it is configured. You can unplug it now.

Repo

Files

Log

Flashes only over your own USB connection; nothing is uploaded. The images are served from this page and written straight to the chip in your browser. Build the firmware yourself with arduino-cli, or use the raw images in the latest release.