Online Flasher

The online flasher tool allows you to flash firmware to your ESP32 device directly from the browser, without installing any development environment.

Note

Online flashing is supported only in Chrome or Edge browsers.

Warning

Use a USB cable that supports data transfer. A charging-only cable may power the board but will not work for flashing or serial connection.

Prerequisites

  • Chrome or Edge browser installed (Web Serial API support required)

  • ESP32 device connected to your computer with a USB data cable before clicking Connect

  • Serial port device recognized in Device Manager

Note

If the device is not found in Device Manager, try using a different USB port.

Note

For the LAFVIN ESP32S3 AIChatBot on Windows, connect the USB Type-C data cable to the ESP32-S3 UART port for online flashing. On macOS, use the USB port and follow the macOS download-mode note below.

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Flashing Steps

  1. Open the online flasher: LAFVIN Web Flasher

    ../_images/olf2.png

  2. Select your kit or device model.

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  3. Select the firmware to flash.

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  4. Select the firmware version.

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  5. Connect the device to your computer before clicking Connect. You may plug in the device after opening the flasher page, but it must be connected before this step.

  6. Click Connect. A serial port selection window will pop up in the upper-left corner of the browser (grant permission if prompted). Select your device and click Connect. Once connected, the button will change to Disconnect.

    ../_images/olf6.png ../_images/olf7.png

Note

When using online flashing on macOS, connect the USB Type-C cable to the ESP32-S3 USB port instead of the UART port. Then press and hold BOOT, press RESET while still holding BOOT, and enter download mode before clicking Connect or starting the flash process. The screen will turn black after the device enters download mode; this is normal.

Entering Download Mode on macOS

  1. Select the Flash Baud Rate and whether to enable Erase Flash (recommended for first-time flashing). Once confirmed, click Flash. The tool will automatically erase and write the selected firmware.

    ../_images/olf8.png

Note

The Flash erase process may take a while. Please be patient.

After flashing is complete, restart the device by pressing the RST or RESET button on the ESP32-S3 board. You usually do not need to unplug the USB cable.

Alternative Help

If online flashing does not work, use the following system-specific references:

  • Windows: If the serial port does not appear or the device cannot connect, see Driver Installation for CP210x driver installation and Windows 11 troubleshooting.

  • macOS: Online flashing is still recommended first. If it does not work, see macOS Firmware Upload (Alternative) for the local macOS flashing alternative.