Near Field Communications (NFC) has been part of mobile phones since 2012, when Google launched the first NFC-enabled phone, the Google Nexus S. Most Android phones have NFC reading technology. Apple added their NFC technology in 2014 with the iPhone 6/6+ but tag reading is limited to the iPhone 7 and newer. Information on how to enable your phones to read NFC tags is here.

While the primary use of NFC technology today is to make electronic payments, reading and writing NFC tags is certainly possible with the proper software and compatible tags.

In May 2021, Chrome for Android 91 came out - that and subsequent versions supports Web NFC – any web developer can experiment and use NFC from simple HTML pages (rather than an app). Apple’s Safari and other browsers may provide limited support beyond Chrome (see this page for current test suite results).

Web NFC lowers the barrier to play for the developers and – more importantly – NFC functionality can now be part of the web: no software installations required.

What is Web NFC

NFC stands for Near Field Communications and is a short range wireless technology operating at 13.56 MHz. Short range really means short range: in order to communicate, the devices have to be just a few centimeters apart or less.

There are four operating modes defined by the NFC Forum: reader/writer, peer-to-peer, card emulation and wireless charging. Of these four modes, only the first one – reader/writer – and only the so-called NDEF specification - is supported by Web NFC. NDEF is the NFC Data Exchange Format and describes a standardized way to encode data onto NFC tags and read it back. For example, it defines how text is encoded or how URLs can be encoded in a byte-saving manner.

So just be clear: you will not be able to emulate a credit card with NFC for in-store payments, nor will you be able to “turn on NFC wireless charging” via Web NFC. But everything that deals with reading and writing little snippets of data to NFC tags in the standardized NDEF format is in.

Parts

The following Adafruit parts were used to test Web NFC functionality:

NTAG203/213 Modern Tags