While Web Bluetooth is not yet a W3C standard, there is a community behind it and they are pushing the agenda forward. If you have a Feather Bluefruit LE product you can attempt this blink project, with most support being offered for the Chrome browser.
You can find the demo on this website near the bottom under the Arduino Firmata – Adafruit Feather heading.
Featured Adafruit Products!
Adafruit Feather 32u4 Bluefruit LE: This is the Adafruit Feather 32u4 Bluefruit – our take on an ‘all-in-one’ Arduino-compatible + Bluetooth Low Energy with built in USB and battery charging. Its an Adafruit Feather 32u4 with a BTLE module, ready to rock! Read more.