Practical, plain-language guides on NFC tags: how they work, what they're used for, and how to read, write and inspect them with NFCore.
NXP's NTAG 22x DNA StatusDetect chips turn a single NFC tap into three things at once: proof a product is genuine, proof a seal wasn't broken, and a battery-free sensor reading. Here's what StatusDetect adds over standard NTAG tags, how conductive and capacitive tamper detection differ, and where you'll actually run into these chips.
NFC tags are rated for 100,000 write cycles and 10 years of data retention, but adhesive wear and moisture usually cause failure first, not the chip.
An NFC social media tag stores one link and opens it the instant someone taps their phone to it — no app required on their end. This guide covers what to write to the tag, whether to point it at one profile or a link-in-bio hub, and how to fix the most common tap-doesn't-work problems on iPhone and Android.
A tap on a yard sign or an open-house card can send a buyer straight to the listing page or hand an agent's contact info to their phone, no app required on most modern devices. Here's which NFC chip to buy, which record type belongs on which piece, how to write and mount both without extra hardware, and what to check when a tag doesn't read the way it should.
NameDrop needs no setup but only works iPhone-to-iPhone with a confirmation step every time. An NFC contact tag takes a minute to write once, then works across iPhone and Android for as long as you carry it. Here's how each actually works, and which one to reach for.
NFC tag capacity isn't one number — it depends entirely on which chip is inside the sticker or card. Here's exactly how many bytes NTAG213, NTAG215, NTAG216, NTAG 424 DNA, and MIFARE tags actually hold, and what that means for what you can write to them.
If an NFC tag opens Safari instead of an app on iPhone, the tag isn't the problem — the URL isn't a working universal link. Here's what background NFC reading actually checks, and the setup mistakes that break it silently.
Password protection and permanent locking both stop a tag from being rewritten, but only one of them can be undone. Here's how PWD/PACK/AUTH0 differ from lock bytes, and how to pick the right one.
Not sure if your phone can tap-to-pay or read NFC tags? Here's the quickest way to check on Android and iPhone, plus what to do if NFC won't turn on.
Tap to Pay on iPhone lets a merchant accept contactless payments straight from their own phone — no card reader, dongle, or terminal required. Here's how the Secure Element keeps the tap safe, what customers can pay with, and where the feature still has limits.
NTAG 424 DNA doesn't just store a static NDEF link — it rewrites part of that link on every single tap, using AES-128 and a rotating counter to prove the scan is genuine. Here's how SUN and SDM actually work, and where you'll run into them.
How brands use cryptographic NFC chips like NTAG 424 DNA to stop counterfeiting — and why a plain NFC tag can't do the same job.
A tap-to-review tag puts your Google review link one phone tap away from checkout. Here's how the tag works, how to set it up correctly, and where Google draws the line on asking for reviews.
Most NFC tags aren't one-and-done — erasing and reformatting clears the stored NDEF message so the same tag can carry new content. This guide covers what actually gets wiped, how Android and iPhone differ, and why a locked tag won't erase.
ISO 15693 is the vicinity-card standard behind NXP's ICODE tags — built for reading at a distance, not a deliberate tap. Here's how it differs from the NTAG/MIFARE tags you already know, where it actually shows up, and what it takes for a phone to read one.
Every NFC tag has a UID field in NFCore's inspector, and it looks like just another piece of data. It isn't. Here's what the UID actually is, why it's locked at the factory, and where it's a reliable tool versus where it isn't.
If an NFC tag reads perfectly on your desk but goes dead once you stick it on a metal panel, it's not the tag or your phone — it's the metal. Here's the mechanism behind it, and the two practical fixes: a purpose-built anti-metal tag, or a thin spacer that buys you a working read on a standard one.
NFC Forum Tag Types 1–5: What the Numbers Actually Mean
FeliCa is the contactless standard — known as NFC-F — behind Japan's Suica, PASMO, and Osaifu-Keitai systems. Here's how it works, where you'll run into it, and what your phone can and can't read from one.
A tap on a $0.30 sticker can replace a five-step settings routine. Here's how Android's NFC tag dispatch connects to Tasker, plus a starter automation you can build today.
Host card emulation (HCE) lets an app turn your phone into an NFC card without any dedicated secure element chip. Here's how AID routing and APDU exchange actually work, where you already run into HCE, and why iPhone still lags behind Android on it.
You've read the basics — now here's the layer built for repeat projects. Templates save a tag's contents for reuse, Batch Write applies that template across a stack of tags, and the Tag Inspector shows exactly what's on a tag, NDEF or not. Here's how the three fit together in NFCore.
A practical buyer's guide to NFC tags: which chip size to get, why NTAG21x beats MIFARE for most projects, and the frequency mismatch that ruins the most common purchase.
URL and Text are just two of the record types NDEF supports. Custom records — MIME and External Type — are how Smart Posters, Bluetooth pairing tags, and app-specific data actually get built. Here's what's under the hood, and how to write one yourself with NFCore.
An NFC emergency medical tag lets a stranger tap your phone and see your allergies, conditions, and an ICE contact — but it's a storage feature, not medical advice. Here's what to put on one, how it compares to your phone's built-in Medical ID, and the privacy tradeoff worth knowing before you turn it on.
NFC security gets talked about like it's one thing, but a plaintext smart-poster tag and a tap-to-pay transaction sit in completely different risk categories. Here's what sniffing, replay, and relay attacks actually require, why NFC's short range is a real defense and not just marketing, and what's worth doing something about.
Tapping your phone to pay looks the same whether you're on iOS or Android, but the two systems protect your card number in different ways — one in a dedicated chip, one in software. Here's what actually happens during that tap.
NFC works at a few centimeters on purpose. Here are the real numbers — 5 mm certified, ~4 cm typical — and the 13.56 MHz magnetic-coupling physics that keeps the range short, plus how to fix taps that won't read.
There's no universal winner in NFC vs QR code. QR wins restaurant menus on cost, Wi-Fi sharing is roughly a tie, and NFC takes premium business cards.
NFC inventory tracking puts a tappable tag on every asset. Here's how to pick a tag, write an ID, build a tap-to-log workflow, and decide when NFC beats barcodes or RFID.
The wristband at a festival is a 13.56 MHz NFC chip handling entry, cashless payments, and ID. Here's how it works and what your own phone can read off it.
Put an NFC tag behind every exhibit label so visitors tap a phone for audio, translations, and artist notes. Here's how to deploy it, step by step.
Put an NFC tag on your pet's collar so any phone can tap to reach you. Here's what to store, which chip to buy, and why it supplements the implant.
Stick an NFC tag on each pot, write a care note or watering Shortcut to it, then tap to log or check what the plant needs. Here's how to set it up.
An NFC sticker is an NTAG chip and antenna laminated in paper, PET, PVC, or epoxy. Here's how each material holds up — and why metal needs a special tag.
"Tag Not Supported" usually means the chip is fine but your phone can't read it. Here are the five most common causes — and the fix for each one.
Raw NFC commands are bytes you send straight to the chip. Here is how READ, WRITE, and ISO 7816-4 APDUs work, and what the Command Console sends.
A memory dump shows every byte on an NFC tag as hex and ASCII. Here is how the pages are laid out, how to read a dump, and what each block means.
Locking an NFC tag is a one-way switch that makes it read-only forever. Here is how lock bytes work and when permanent locking actually makes sense.
MIFARE DESFire is the secure, AES-based smart-card chip behind most transit and building-access cards. Here is how EV1, EV2, and EV3 differ and what they do.
Cloning a tag you own usually means copying its NDEF data to a blank tag, which is easy. Copying the fixed UID is a different story. Here is what works.
Tap an NFC tag to run a HomeKit scene or a Home Assistant automation, and use Matter's new tap-to-commission setup. Here's how each one works and what to buy.
Stick a 50-cent NFC tag on your desk, dashboard, or nightstand. Tap it, and iOS Shortcuts fires the automation you want — Focus on, lights off, playlist on.
iPhone and Android both read and write the same NDEF tags. The differences live at the edges — card emulation, MIFARE Classic, background triggers.
Three ways to put your contact info on an NFC tag — a vCard MIME record, a URL record, or a Smart Poster — and which one fits your audience, tag chip, and update cadence.
Encode your Wi-Fi credentials on an NFC tag so guests connect by tapping their phone. Here's the record format, the iPhone caveat, and how to pick a tag.
Writing an NFC tag means saving an NDEF message to it from your phone: a link, text, contact, or Wi-Fi. Here's how to do it on Android and iPhone.
Two ways to read NFC tags on iPhone: background reading on XS and newer, or a manual scan from Control Center or an app. Here's exactly how each one works.
MIFARE is the NXP chip family inside most NFC cards you tap. Here's what Ultralight, Classic, and DESFire are, what your phone reads, and which one to pick.
NTAG213, 215, and 216 are the same NXP chip family with different memory. Pick the smallest one that fits your payload — here's how to decide.
NDEF is the NFC Forum's standard application-layer format — the wrapper every consumer NFC tag uses so any compliant phone reads the same bytes the same way. Here is how its messages, records, and TNF values fit together.
Four wireless radios, four jobs. NFC for the tap, RFID for the warehouse, Bluetooth for the headset, Wi-Fi Direct for the file — explained with numbers.
NFC is two ideas stacked on each other — a short-range magnetic link at 13.56 MHz and a record format called NDEF that any phone can read. Once you've seen one record, you've seen all of them.
NFC tags are tiny, battery-free chips that send data to a phone with a single tap. Here's what's actually inside one, the different types you'll encounter, and the practical things people use them for.