ESP Web Tools

ESP Web Tools is a set of open source tools to allow working with ESP devices in the browser. The code is available on GitHub.

To try it out and install ESPHome on an ESP, connect it to your computer and hit the button:

Note, this only works in desktop Chrome and Edge. Android support should be possible but has not been implemented yet. If you don't see your ESP device, you might miss drivers.

This works by combining Web Serial with a manifest which describes the firmware. It will automatically detect the type of the connected ESP device and find the right firmware files in the manifest.

Products using ESP Web Tools

Adding ESP Web Tools to your website

To add this to your own website, create a manifest and add the button to your website. Make sure you update the manifest attribute to point at your manifest.

You can import ESP Web Tools directly from the unpkg CDN or download the files and put them on your website.

<script
  type="module"
  src="https://unpkg.com/esp-web-tools@5.1.0/dist/web/install-button.js?module"
></script>

<esp-web-install-button
  manifest="static/firmware_build/manifest.json"
></esp-web-install-button>

Your website needs to be served over https://. If your manifest is hosted on another server, make sure you configure the CORS-headers for your manifest and firmware files such that your website is allowed to fetch those files by adding the header Access-Control-Allow-Origin: https://domain-of-your-website.com.

ESP Web Tools can also be integrated in your projects by installing it via NPM:
npm install --save esp-web-tools

Creating your manifest

ESP Web Tools manifest describe the firmware that you want to install. It allows specifying different builds for the different types of ESP devices. Current supported chip families are ESP8266, ESP32, ESP32C3 and ESP32S2. The correct build will be automatically selected based on the type of the ESP device we detect via the serial port.

{
  "name": "ESPHome",
  "version": "2021.11.0",
  "home_assistant_domain": "esphome",
  "new_install_skip_erase": false,
  "builds": [
    {
      "chipFamily": "ESP32",
      "parts": [
        { "path": "bootloader.bin", "offset": 4096 },
        { "path": "partitions.bin", "offset": 32768 },
        { "path": "ota.bin", "offset": 57344 },
        { "path": "firmware.bin", "offset": 65536 }
      ]
    },
    {
      "chipFamily": "ESP8266",
      "parts": [
        { "path": "esp8266.bin", "offset": 0 }
      ]
    }
  ]
}

Each build contains a list of parts to be flashed to the ESP device. Each part consists of a path to the file and an offset on the flash where it should be installed. Part paths are resolved relative to the path of the manifest, but can also be URLs to other hosts.

If your firmware is supported by Home Assistant, you can add the optional key home_assistant_domain. If present, ESP Web Tools will link the user to add this device to Home Assistant.

By default a new installation will erase the entire flash. If you want to skip this step, set the optional key new_install_skip_erase to true. ESP Web Tools considers it a new installation if it is unable to detect the current firmware of the device (via Improv Serial) or if the detected firmware does not match the name specififed in the manifest.

Wi-Fi provisioning

ESP Web Tools has support for the Improv Wi-Fi serial standard. This is an open standard to allow configuring Wi-Fi via the serial port.

If Improv is supported, a user will be guided to connect the device to the network after installation. It also allows the user to connect already installed devices and re-configure the wireless network settings.

Customizing the look and feel

There are multiple options to change the look and feel of the button and other elements.

Change colors

You can change the colors of the default UI elements with CSS custom properties (variables), the following variables are available:

• --esp-tools-button-color
• --esp-tools-button-text-color

There are also some attributes that can be used for styling:

install-supported	Added if installing firmware is supported
install-unsupported	Added if installing firmware is not supported

Replace the button and message with a custom one

You can replace both the activation button and the message that is shown when the user uses an unsupported browser or non-secure context with your own elements. This can be done using the activate, unsupported and not-allowed slots:

<esp-web-install-button
  manifest="static/firmware_build/manifest.json"
>
  <button slot="activate">Custom install button</button>
  <span slot="unsupported">Ah snap, your browser doesn't work!</span>
  <span slot="not-allowed">Ah snap, you are not allowed to use this on HTTP!</span>
</esp-web-install-button>
    

USB Serial Drivers

If the serial port is not showing up, your computer might be missing the drivers for the USB serial chip used in your ESP device. These drivers work for most ESP devices:

• CP2102 (square chip): driver
• CH341: driver