HDZap Firmware Installer

Flash the M5StickS3 directly from your browser.

Supported device

M5StickS3 only. ESP32-S3 with native USB-C.

Other ESP32-S3 boards (DevKitC, XIAO, AtomS3, etc.) will accept the flash, but HDZap won't work correctly because the LCD, PMIC, buttons, and speaker wiring differ.

This browser is not supported

Your browser does not support the Web Serial API. Please open this page in Google Chrome, Microsoft Edge, or another Chromium-based browser (Brave, Opera, Vivaldi, Arc, etc.) on macOS or Windows.

Safari, Firefox, and all iOS browsers are unsupported.

Install

Plug the M5StickS3 into your computer with a USB-C data cable (charge-only cables won't be detected).
Hold the power button (the small one) on the left side for 2 seconds to enter flash mode. The green LED starts blinking when you're in.
Click the button below and select the M5StickS3 serial port in the browser dialog.
- macOS: cu.usbmodem...
- Windows: COMx
Flashing takes about 30–90 seconds. When it's done, press the power button once to boot HDZap.

Erase everything — also wipes saved UID, pairing data, and sleep settings. Usually leave this unchecked.

Version: loading…

When things don't work

The M5StickS3 doesn't show up in the port picker. Hold the power button for 2 seconds — the device must be in flash mode (green LED blinking). If it still doesn't show up, try a different USB-C data cable. On Windows, drivers may take a few seconds to install on first connect.
"Couldn't connect to the bootloader" appears. Hold the power button for 2 seconds, confirm the green LED is blinking, then click "Connect & flash". Without flash mode the connection will fail.
"Couldn't open the serial port" appears. Make sure no other application (PlatformIO serial monitor, Arduino IDE, etc.) is using the same port.
The browser refuses to connect at all. Use a Chromium-based browser (Chrome / Edge / Brave / Opera / Vivaldi / Arc) and check the page is served over https:// or localhost.
The power button doesn't boot the device after flashing. Check the battery level. Pressing the power button while the USB-C cable is still connected gives the most reliable boot.