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Every page published on NFC.GUIDE, grouped by section. Robots looking for the machine readable version will find it at /sitemap.xml.
Guides
Understanding NFC
- What is NFC and how does it work?
- Why does NFC use 13.56 MHz and not another frequency?
- Is NFC a radio wave or a magnetic field?
- How does a phone power a tag that has no battery?
- What is load modulation, and why does a tag never transmit?
- Why can a reader and a tag never speak at the same time?
- What happens, step by step, when a tag enters the field?
- How fast is NFC, and what fits in that speed?
- What is the real read range of an NFC tag?
- Why does NFC need no pairing?
- Can NFC transfer power as well as data?
- How much battery does NFC actually use?
- Does NFC work without an internet connection?
- What does the NFC Forum actually decide?
- What is ISO/IEC 14443, and which tags follow it?
- ISO/IEC 18092 and ISO/IEC 14443: what is the difference?
- What is ISO/IEC 15693, and when do you meet it?
- What are the five NFC Forum tag types?
- What is NDEF, and why does every readable tag use it?
- What is the capability container on a tag?
- Why do Japanese transit cards not work with most NFC apps?
- Is MIFARE Classic really NFC?
- What is a tag UID, and can it be changed?
- Which standard applies to a contactless bank card?
- What are the three NFC operating modes?
- What is reader writer mode?
- What is card emulation, and what does it require?
- What is host card emulation on Android?
- What is a secure element, and where does it sit?
- What was peer to peer mode, and what replaced it?
- Active and passive communication explained
- What is anticollision, and when does it matter?
- Can a phone read two tags at the same time?
- Can a phone be a tag and a reader at the same time?
- Why does NFC fail on metal?
- What is antenna detuning?
- Does water block NFC?
- Does a phone case block NFC?
- Does NFC work through glass, wood and plastic?
- Why does antenna size change read distance?
- Does the reader or the tag determine the range?
- Can NFC interfere with wireless charging?
- What temperature can an NFC tag survive?
- How long does an NFC tag last?
- Can a magnet erase an NFC tag?
- NFC vs RFID vs Bluetooth: what is the difference?
- NFC vs QR code: which one for which job?
- NFC vs barcode for labelling and traceability
- NFC and magnetic stripe: what replaced what
- NFC vs Bluetooth Low Energy
- NFC vs UHF RFID for inventory
- NFC vs ultra wideband
- NFC and Wi-Fi Direct for transferring files
- Do AirDrop and Nearby Share use NFC?
- NFC vs infrared: can a phone replace a remote control?
- Is NFC the same thing as contactless?
NFC tags and cards
- How do you choose NFC tags and cards?
- Which NFC chip should you choose, and on what criteria?
- Which chips work with both Android and iPhone?
- NTAG or MIFARE Ultralight: does the difference matter to you?
- When do you actually need more than the cheapest chip?
- Does the chip itself change the read distance?
- What does write endurance mean in practice?
- Do you need a chip with password protection?
- Which chip suits a digital business card?
- Which chip suits a tag that many people will tap?
- What changes if a chip is not NFC Forum compliant?
- How much can you actually store on an NFC tag?
- Why is usable memory smaller than the packaging says?
- How long a URL fits on the smallest common tag?
- Do you ever need a high capacity tag?
- Does more memory mean a slower read?
- Store on the tag, or store on a server?
- How many contacts fit on one tag?
- Can you put an image on an NFC tag?
- What happens when you fill a tag completely?
- Sticker, card, keyfob or disc: which form factor?
- What is an NFC tag physically made of?
- Which adhesive holds on which surface?
- PVC, PET or paper: which substrate lasts?
- Are wooden and bamboo NFC cards a good idea?
- Are metal NFC cards usable?
- Can an NFC tag be printed on?
- Can an NFC tag be laminated?
- Can you cut an NFC tag to size?
- What tag size do you need for a given read distance?
- Are NFC wristbands and rings practical?
- How does antenna shape affect performance?
- Why does the same tag read differently on two phones?
- What read distance can you realistically promise a client?
- Does stacking two tags work?
- How close can two tags be placed?
- Does a tag inside a wallet still read?
- What happens when a tag is bent?
- Does tag orientation matter?
- Why do bigger tags not always read better?
- What makes an on metal tag different?
- Do you need a waterproof tag, and what does the rating cover?
- Which tags survive industrial temperatures?
- Are laundry tags worth it?
- What is a tamper evident NFC tag?
- What are NFC tags with a built in sensor?
- What is a dual interface card?
- Are combined NFC and RFID tags useful?
- What is an inlay, and when do you buy one?
- Are anti metal spacers a substitute for on metal tags?
- Which tag suits outdoor use?
- How do you tell a good tag from a bad one before buying?
- Why do cheap tags fail more often?
- What should a tag supplier be able to tell you?
- How do you check which chip you actually received?
- What quantity should you order for a first deployment?
- Do NFC tags have a shelf life?
- How should tags be stored before use?
- What is an acceptable failure rate in a batch?
- Should you buy pre encoded tags?
- Which certifications matter for NFC tags?
Writing NFC tags
- How do you write an NFC tag?
- What is an NDEF message, and how is it built?
- How many records can one tag hold, and should it?
- What is TNF, and why does it change what happens on tap?
- In what order are multiple records acted on?
- Which NDEF records does iOS actually act on?
- How much tag memory does NDEF overhead consume?
- What happens when an NDEF message exceeds the tag?
- Can a tag hold data that is not NDEF?
- Writing and formatting a tag are not the same thing
- Does writing a tag erase what was on it?
- How do you write a URL to an NFC tag?
- Why are URL prefixes abbreviated on a tag?
- How do you write plain text, and who reads it?
- How do you write Wi-Fi credentials to a tag?
- Why does a Wi-Fi tag work on Android but not on iPhone?
- How do you write a contact card to a tag?
- Which record type should you choose for a business card?
- How do you write a phone number that triggers a call?
- How do you write an email with a prefilled subject?
- How do you write an SMS to a tag?
- How do you write geographic coordinates to a tag?
- How do you make a tag open a specific app?
- What is an Android Application Record?
- Can one tag carry more than one action?
- Does a new tag need to be formatted before use?
- What does formatting an NFC tag actually do?
- How do you check how much free space a tag has?
- How do you erase an NFC tag?
- Can a tag be returned to its factory state?
- What can you configure on a tag besides its content?
- Can you prepare tags before you know the content?
- Why you should test a tag before deploying it
- How do you write to a tag that is already stuck to a surface?
- What does locking an NFC tag actually do?
- Can a locked NFC tag be unlocked?
- When should you lock a tag, and when should you not?
- Locking or password protection: which one do you need?
- How do you set a password on a tag, and what does it protect?
- Can you lock only part of a tag?
- Can a tag be protected from being read?
- What happens if you lose a tag password?
- Is a locked tag really safe from being overwritten?
- Should a public tag be locked before deployment?
- How do you write hundreds of tags without doing it one by one?
- Can every tag in a batch carry a different URL?
- How do you keep track of which tag holds what?
- Should tags be written before or after being applied?
- How long does it take to write a batch of tags?
- What goes wrong when writing a large batch?
- How do you verify a batch was written correctly?
- How do you handle a tag that fails during a run?
- Factory encoded tags: when are they worth it?
- How do you copy the content of one tag to another?
- How do you back up a tag before overwriting it?
- Why can a copied tag behave differently from the original?
- Can you copy a tag onto a different chip type?
- Can you copy a tag whose UID matters?
- Why does copying a transport card not work?
- How do you replace a damaged tag without changing anything else?
- How do you migrate a deployment to new tags?
NFC on smartphones
- What can a smartphone actually do with NFC?
- How do you turn NFC on and off on Android?
- What does Android do automatically when you tap a tag?
- What is Android's tag dispatch system?
- Where does Android show what a tag contains?
- Can an app take priority over the system on tap?
- How do you stop Android opening a tag automatically?
- Can Android write every kind of tag?
- Does Android read tags with the screen off?
- Which Android versions support which NFC features?
- Why do some Android phones read tags others cannot?
- Can Android emulate a card without a secure element?
- Does a work profile or an MDM affect NFC?
- Which iPhones can read NFC tags?
- Which iPhones can write NFC tags?
- Why must an NFC app be launched manually on iPhone?
- Why does an iPhone show a scan sheet when an app reads a tag?
- How do you read a tag on iPhone without an app?
- Does the iPhone read tags when locked?
- Why does the iPhone show a banner instead of opening the link?
- Why does iOS refuse some Wi-Fi and app records?
- Does iOS support tag locking and passwords?
- Can an iPhone emulate an access badge?
- What changed for NFC across recent iOS versions?
- Can an iPad or an Apple Watch read NFC tags?
- Where is the NFC antenna on a phone?
- Why is a phone's NFC antenna so small?
- Do foldable phones behave differently with NFC?
- Why does NFC stop working after a phone repair?
- Do rugged phones read NFC tags reliably?
- How many tags can you read in a row on a phone?
- How do you choose phones for an NFC deployment?
- Are external NFC readers worth it for phones?
- What does a dedicated reader add over a phone?
- How do you tell a visitor where to hold their phone?
- When is a phone actually listening for tags?
- Does background reading drain the battery?
- Does background reading work in aeroplane mode?
- Does NFC work without a SIM or mobile data?
- Does NFC work while the phone is doing something else?
- Why does the same tag trigger twice?
- How do you disable background reading?
- What permissions does an NFC app need?
- Does a phone keep a history of the tags it has read?
- Can NFC tags work as an accessibility aid?
NFC automation
- What can you actually automate with an NFC tag?
- How do you set up guest Wi-Fi sharing at home?
- Where should a guest Wi-Fi tag be placed?
- Is a Wi-Fi tag a security risk?
- How do you update a Wi-Fi tag after a password change?
- How do you make a Wi-Fi tag for a holiday rental?
- Can one tag hold two networks?
- Can a Wi-Fi tag work with enterprise networks?
- Can a tag connect to a hidden network?
- Is an NFC tag a good way to share your contact details?
- How do you share a social profile by tap?
- How do you share a payment link by tap?
- Can a tag hold several ways to reach you?
- How do you change what your tag shares later?
- What personal data should never go on a tag?
- How do you make an emergency information tag?
- Can a tag identify a pet or a piece of luggage?
- What can an NFC tag control at home?
- How do you link a tag to a smart home system?
- How do you make a tag turn the lights on?
- Can a tag trigger a whole scene?
- How do you make a bedtime tag?
- Where do you place tags so they get used daily?
- Does a home automation tag need the internet?
- Can several people share the same home tag?
- Can a tag arm and disarm an alarm?
- What happens to your tags if you change platform?
- How do you make a tag change phone settings?
- How do you build a tag driven routine on Android?
- How do you build a tag driven shortcut on iPhone?
- Can a tag turn on do not disturb?
- Can a tag start a timer or a countdown?
- Can a tag log something automatically?
- How do you make a tag send a message?
- Can a tag toggle between two states?
- How do you chain several actions to one tap?
- Which routines are actually worth automating?
- How do you test a routine before relying on it?
- Why does my routine tag not work for a guest?
- Why do routines stop working after an update?
- What survives when you change phone?
- What is a car mode tag, and does it help?
- Can a tag start navigation to a saved place?
- When should you not use a tag in a car?
- Can an NFC tag unlock or start your car?
- Can a tag work in a car several people drive?
- Can a tag start a video call?
- Can a tag tell others you are in a meeting?
- Can a tag open a shared board or document?
- Can a tag clock you in and out?
- Can a tag start music on a speaker?
- How do you make a tag for a playlist?
- Can a tag point to a video you filmed?
- How do you build a tag driven board game aid?
- Can tags be used in an escape game?
- How do you make a tag treasure hunt?
- Can a tag launch a podcast episode?
- What makes a good tag based gift?
- Can tags replace a physical album for children?
NFC for business
- Where does NFC pay for itself in a business?
- How does an NFC business card actually work?
- Card, sticker or keyfob for a business card?
- What happens when a prospect taps your card?
- What should the page behind your card show?
- How do you update your details after handing out cards?
- Do NFC business cards work on every phone?
- What do you do when someone has no NFC phone?
- How do you equip a whole team with NFC cards?
- How do you measure whether a card is used?
- What does an NFC business card deployment cost?
- What can an NFC tag do on a shelf display?
- How do you place tags in a shop so they get used?
- What signage does a tag need next to it?
- How do you handle tags on metal shelving?
- Can one tag serve several products?
- How do you set up a tap to review tag?
- Can NFC replace a printed catalogue?
- How do you refresh a campaign without replacing the tags?
- How are NFC badges used at an event?
- Should badges be encoded before or on site?
- How many spare badges should you prepare?
- How do you handle badge failures during an event?
- Can a badge work without network coverage?
- Can attendees exchange details by tapping badges?
- What data should never be written on a badge?
- What do you do with badges after the event?
- Can NFC tags be used for door access?
- Why is a plain NFC tag not an access credential?
- What distinguishes an access badge from a data tag?
- Can phones replace access badges?
- What happens when a badge is lost?
- How do you audit an existing badge system?
- What should you ask an access control supplier?
- When is NFC the right choice for inventory?
- How many items can one person scan per hour with NFC?
- How do you tag equipment for maintenance?
- What do you write on an asset tag?
- How do you tag metal equipment?
- How do you plan a tagging scheme for a fleet?
- What do you do with a tag that outlives the asset?
- Can NFC track items through a supply chain?
- Should packaging carry a tag, a QR code, or both?
- How do you put a tag inside a product package?
- How do you tag a printed poster?
- How do you tag a product that will be shipped?
- What response rate can you expect from a tap campaign?
- What should a packaging tag do after purchase?
- What happens to NFC tags in packaging recycling?
- How do you plan an NFC deployment from scratch?
- What does a pilot deployment need to prove?
- How do you budget a deployment of a thousand tags?
- Who encodes the tags, and when?
- Which device should encode the batch?
- How do you write one tag that works on every phone?
- How do you test a tag on both platforms before deploying?
- What can you promise a client about iPhone support?
- Which platform limits will not be lifted by an update?
- How do you handle replacements over time?
- What documentation should a deployment leave behind?
- How do you hand a deployment over to a client?
NFC security and privacy
- How safe is NFC, and what can it expose?
- What can actually be cloned from an NFC tag?
- Can someone copy your NFC business card?
- Can an access badge be cloned?
- Can a tag be cloned without touching it?
- Can a phone clone a tag on its own?
- Can a bank card be cloned by tapping it?
- Can a passport or an ID be read without consent?
- Is your tag worth cloning to anyone?
- How do you tell if a tag is a clone?
- How do you protect a deployment against copying?
- What is a signed NDEF record, and what does it prove?
- Can a tag prove it is genuine?
- What is tag authentication, and which chips offer it?
- Does password protection authenticate anything?
- What is a rolling code on a tag?
- Who verifies that a tag is genuine?
- How do brands authenticate products with NFC?
- Can a tag be tied to a single phone?
- When is cryptographic authentication worth its cost?
- How safe is contactless payment, really?
- What happens if you tap a terminal you do not trust?
- What does a payment terminal actually receive?
- Do RFID blocking wallets do anything?
- Why is a phone payment safer than a card tap?
- What happens if your phone is stolen?
- Who pays when a contactless payment is fraudulent?
- What data is on a contactless card?
- Why do contactless payment limits exist?
- Can an NFC tag track you?
- What does a tag learn about the phone that reads it?
- Can a tag read data from your phone?
- What does the site behind a tag see?
- Is leaving NFC on a privacy risk?
- Could somebody track you with a tag hidden in your things?
- What are the privacy duties of a public tag?
- What should a tag driven landing page disclose?
- Do NFC tags fall under data protection rules?
- Can an NFC tag be disabled permanently?
- Can an NFC tag carry a virus?
- Can someone hack your phone through a tag?
- Is NFC dangerous for health?
- Does NFC work when your phone is switched off?
- Can a tag be changed remotely?
- Can you tell what a tag holds by looking at it?
- Do NFC tags need to be registered or activated?
- Is a QR code safer than an NFC tag?
- Is it safe to tap a tag in a public place?
- What should you do after tapping an unknown tag?
NFC troubleshooting
- Why is my NFC tag not working?
- Nothing happens when I tap the tag: where to start
- A brand new tag does not respond at all
- The phone vibrates but nothing opens
- The tag is detected but no action runs
- The tag reads but opens the wrong thing
- The tag works on one phone but not another
- My tag only works sometimes
- My tag stopped working after a while
- The tag works in the app but not from the lock screen
- My tag only reads when touching: is that normal?
- Read distance dropped after installation
- One tag in a batch reads much worse than the others
- The tag reads on one side of the phone only
- I cannot find the right spot on my phone
- Reading works standing still but not in passing
- Reads get worse when the battery is low
- Two identical phones give different read distances
- My tag stopped working once stuck on metal
- The tag fails inside a car
- The tag fails on a fridge or an appliance
- My tag fails outdoors in cold weather
- The tag stopped working after getting wet
- Another tag nearby breaks the read
- The tag fails near a wireless charger
- The tag fails behind glass or a screen protector
- I locked my tag by mistake: what now?
- The tag says read only and I did not lock it
- I forgot the password I set on a tag
- A pre encoded tag cannot be rewritten
- Writing fails with a protection error
- How do I know if a tag is locked before writing?
- The tag is not locked but still refuses writing
- The tag accepts writing but the content disappears
- My phone does not detect any tag
- Does my phone even have NFC?
- Is NFC enabled? How to check on Android and iPhone
- NFC disappeared from my phone settings
- NFC stopped working after a system update
- NFC works after a restart, then fails again
- My iPhone does not read tags automatically
- NFC works for payment but not for tags
- My phone reads tags but cannot write them
- Writing fails halfway through
- The message is too large for the tag
- The URL is truncated after writing
- The tag opens a search instead of my site
- Writing succeeds but the action does not trigger
- A URL writes fine but Wi-Fi or a contact fails
- Accented characters come back wrong after writing
- Writing corrupted the tag
NFC for developers
- How do you read and write NFC from your own code?
- Reader mode or foreground dispatch: which one should an Android app use?
- How do you declare the tags an Android app should receive?
- Which technology class should Android code open for a given tag?
- How do you write an NDEF message from an Android app?
- Can an Android app react to a tag without showing a screen?
- How do you handle a tag that arrives while your activity is open?
- Which controller limits must Android code check at runtime?
- NDEF session or tag session: which one should an iOS app open?
- What does an iOS app have to declare before it can read a tag?
- How do you write and lock an NDEF tag from an iOS app?
- How does an iOS app receive a tag read in the background?
- How do you read several tags in one iOS session?
- Can an iOS app read a tag's identifier?
- Can a web page read an NFC tag?
- What can Web NFC write, and what can it not?
- Web page or native app: which one for an NFC project?
- Can a cross platform framework reach every NFC feature?
- How do you send a raw command to a tag?
- What is an APDU, and when does your code need one?
- How do you read the memory of a Type 2 tag page by page?
- How do you read the blocks of an ISO/IEC 15693 tag?
- How does code find the NDEF file on a Type 4 tag?
- How does code authenticate to a password protected tag?
- How do you detect that a tag has left the field?
- How do you write a tag so an interrupted write cannot pass for valid?
- How do you write a tag's configuration pages without ruining it?
- How does a server read the identifier a tag mirrors into its URL?
- How does an Android app emulate a card with host card emulation?
- Why does a reader reach another app instead of yours?
- What does an iOS app need to emulate a card?
- Can a phone emulate an NDEF tag for another phone?
- Does host card emulation work with the screen off?
- How does a computer talk to a USB NFC reader?
- Which reader chip suits a microcontroller project?
- Why does a hobby reader module miss some tags?
- What is a dynamic tag, and when does a device need one?
- Can a phone configure a device that is switched off?
- How do you design an NFC antenna for your own board?
- Can your own device act as a tag for a phone?
- Why does a read fail with a tag lost error?
- Why does a Core NFC session end on its own?
- Why does a command time out, and how long should code wait?
- Can NFC code be tested without a tag in hand?
- Which tags should a developer keep for testing?
- How do you see what an app and a tag actually exchange?
- What should an app do when NFC is off or missing?
- Why does code written for one chip break on another of the same type?
- Should an NFC app install on phones without NFC?
NFC in products
- How do you put NFC into a product you manufacture?
- Can a digital product passport be carried by an NFC tag?
- Which products does the digital product passport cover?
- Who hosts the data behind a product passport?
- What can the public read in a product passport, and what stays restricted?
- How long must a product passport stay readable?
- Should a product passport sit in a QR code, a tag, or both?
- Does a passport carrier have to be on the product itself?
- Can a battery passport be read from an NFC tag?
- What goes into the EU registry of product passports?
- Should a product tag carry a GS1 Digital Link?
- What unique identifier does a product passport require?
- Model, batch or item: what should a product tag identify?
- What does a resolver add behind a product tag?
- Where does a tag go in a product with a battery or a metal body?
- Can a tag be moulded into a plastic part?
- How is a tag built into a garment?
- Can a tag be embedded in wood, leather or ceramic?
- Can a product carry the NFC logo?
- How do you test a tag inside a prototype before tooling?
- Should a customer be able to remove or disable a product's tag?
- Can a product tag replace the paper manual?
- Can a tap register a product for its warranty?
- Can a product tag carry its repair history?
- How does a product tag pass to a second owner?
- Can a tag help with a product recall?
- Can a product tag open a different page once the product is sold?
- Can a tag tell a recycler what a product is made of?
- Can a tag run a return or deposit scheme?
NFC by industry
- What changes about NFC from one sector to another?
- What can a hotel put behind a tag in a guest room?
- Can a tag replace a restaurant's printed menu?
- Where does a tag go on a restaurant table?
- Can guests order and pay from a table tag?
- How do museums label exhibits with NFC?
- Can a tag replace an audio guide?
- How do you fix a tag to a plaque or a protected monument?
- Can a city put tags on street furniture?
- Is a race timing chip an NFC tag?
- Can a phone read the tag inside a library book?
- Can a school take attendance with NFC?
- How do you use NFC in a classroom where pupils have no phones?
- What can an estate agent put behind a tag on a for sale sign?
- Can residents report a fault by tapping a tag in their building?
- Can a tag be cast into concrete?
- How do NFC checkpoints prove that a round was done?
- Can a guard fake a round by copying a checkpoint tag?
- Is logging rounds by tap a form of employee monitoring?
- Can a tag keep the inspection record of safety equipment?
- What changes when tags go into a hospital or a care home?
- Which tags survive hospital disinfection?
- Can a patient wristband carry an NFC tag?
The phone as a card
- What can a phone carry instead of a card?
- Which card pays when you tap a phone?
- Why do a phone and a watch count as two different cards?
- Can a watch or a ring replace the phone at a terminal?
- What does a shop need to take contactless payments on a phone?
- How does a phone pay a transit fare?
- Why can a transit gate open without unlocking the phone?
- Can a transit card move from plastic into a phone?
- Why can a transit gate charge the wrong card?
- How can a bus accept a tap with no connection?
- Why do some phone tickets tap and others show a barcode?
- Can a loyalty card in a phone be read by tap?
- Can a home door lock open with a phone?
- Can a hotel room key live in a phone?
- How do you share a car key from a phone?
- Why do identity apps ask you to tap your passport?
- How does a mobile driving licence use NFC?
- How does the European digital identity wallet use NFC?
- Can a phone prove your age without showing your whole ID?
- What happens to cards, keys and IDs when you change phone?
- What happens to keys, tickets and IDs when a phone is lost?