Writing NDEF Records and vCard NFC Tags with the Flipper Zero: Contact Cards, WiFi Configs, and URL Tags
Most Flipper Zero NFC content on this site is about the security side — cloning, emulation, and analyzing access control systems. There's an entirely different, completely legitimate use for the same NFC hardware: writing standard NDEF (NFC Data Exchange Format) records to blank tags for everyday convenience. A tag tapped by any modern smartphone can open a URL, join a WiFi network, or add a contact card, no app required on the receiving end beyond the phone's built-in NFC reader. This guide covers writing NDEF records with the Flipper Zero — smart business cards, WiFi onboarding tags, and URL/action tags — using blank writable NFC tags rather than cloning or emulating anything.
What NDEF Actually Is
NDEF is a lightweight, standardized data format that phones and other NFC readers recognize automatically without a custom app — it's the same format used by retail smart tags, transit posters, and the NFC stickers you'll find in some hotel rooms and product packaging. A tag containing a well-formed NDEF record triggers the phone's default behavior for that record type: opening a browser for a URL record, prompting to join a network for a WiFi record, or offering to save a new contact for a vCard record. This is different from the raw UID cloning and low-level MIFARE work covered elsewhere on this site — you're writing standard, cross-platform-readable data rather than working with a card's security architecture.
Tags You'll Need
You need blank, writable NFC tags compatible with NDEF — NTAG213, NTAG215, or NTAG216 are the most common and widely supported (the same family used for Amiibo figures, covered elsewhere on this site, though that's a different use case). NTAG213 has the smallest memory (about 144 usable bytes) which is enough for a short URL but tight for a full vCard; NTAG215 or NTAG216 give considerably more room and are worth the small price difference if you're writing contact cards with multiple fields. These arrive as blank stickers, cards, or keychain fobs and are inexpensive in bulk.
Writing a URL Tag
- On the Flipper Zero, go to NFC → Extra Actions → Add Manually, and select a blank NTAG21x type matching your physical tag.
- Once the empty tag structure is created, use the NFC app's write function to add an NDEF URI record, entering the target URL.
- Place the physical blank tag against the Flipper's NFC antenna (behind the screen) and confirm the write.
- Test immediately by tapping the written tag with a phone's NFC reader (Android reads NFC by default when unlocked; iPhones since the XS support background NFC reading without opening an app) to confirm the URL prompt appears correctly.
URL tags are the simplest starting point and useful for things like a tag on a 3D printer that links to its maintenance log, a tag on a piece of shop equipment linking to its manual, or a tag on packaging linking to a product page.
Writing a vCard Contact Tag
A vCard record embeds a full contact card — name, phone, email, company, even a photo reference — that a phone offers to save directly to contacts on tap. This is the "smart business card" use case: a laser-engraved metal or wood card (see this site's laser business card guide for the physical card itself) with an embedded NFC tag that hands over your full contact details with a single tap, no typing, no photographing a QR code.
- Prepare the vCard text content in standard vCard 3.0 format:
- Using the Flipper's NFC app (or a companion tool via qFlipper/CLI for more complex records if the on-device editor is limiting), write this as the NDEF payload with a MIME-type or vCard record type to a blank NTAG215/216.
- Keep the vCard fields minimal and essential — name, phone, email, and one URL is usually enough, and keeps the payload well within tag memory limits without needing to trim fields later.
- Test on both an Android phone and an iPhone before finalizing a batch, since contact-card handling differs slightly between platforms and you want to confirm the save-contact prompt appears cleanly on both.
Writing a WiFi Network Tag
Android and iOS both support NDEF WiFi configuration records that prompt a device to join a network on tap, which is genuinely useful for onboarding guests or shop visitors onto a WiFi network without reading a password off a sticky note. The record needs the network SSID, security type, and password encoded in the WiFi NDEF format; write it the same way as a URL or vCard record, selecting the WiFi/network record type in the Flipper's NFC editor.
A practical shop use: a small engraved plaque near the door with an embedded WiFi tag for the shop's guest network, next to a URL tag linking to safety guidelines for visitors — two blank NTAG213 tags, five minutes of writing, done.
Making It Durable
- Adhesive NFC stickers are thin and can be damaged by repeated flexing or moisture; for anything handled often (a business card, a keychain fob) use a rigid tag or embed the adhesive sticker inside a laminated or laser-cut protective layer.
- Metal in close proximity to an NFC tag can detune or block the antenna entirely — if embedding a tag in or near a metal enclosure or engraved metal card, use an "on-metal" rated NFC tag, which includes a ferrite backing layer designed to work despite the metal behind it.
- Test the finished, assembled object (not just the bare tag) after any lamination, embedding, or mounting step, since read range can drop noticeably once a tag is sandwiched in a finished product.
A Note on Locking Tags
NTAG21x tags support a permanent lock command that makes the tag read-only forever — useful once a batch of tags is finalized and you don't want them accidentally overwritten later, but irreversible. Don't lock a tag until you've tested the final written content on multiple devices; there's no way to undo a lock.
This is a small, low-cost way to get practical, everyday value out of hardware most people only associate with security research. A stack of NTAG215 tags costs very little, writes in seconds from the Flipper you likely already own, and turns into contact cards, WiFi onboarding tags, or quick-link tags for shop equipment with no app required on the receiving end.