Buying NFC Tags: A Practical Guide to What's Worth Your Money

Quick answer

Buy an NTAG215-based tag. It's an NFC Forum Type 2 chip with 504 bytes of memory — the sweet spot between the cramped NTAG213 and the overkill NTAG216. Three checks decide whether a listing is worth your money: chip memory size, NTAG family instead of MIFARE, and genuine 13.56 MHz NFC rather than 125 kHz RFID wearing NFC marketing copy. Nail those three and almost any tag you buy will work.

Step-by-step — what to check before you buy

Pick a memory size: NTAG213 vs NTAG215 vs NTAG216

NTAG213, NTAG215, and NTAG216 are the same NFC Forum Type 2 chip family at three memory sizes: 144, 504, and 888 bytes. NTAG213 fits a short URL and not much else — a full vCard or Wi-Fi record can blow past its limit. NTAG215 comfortably holds a URL, vCard, or Wi-Fi record with room to spare, which is why it's the default we'd recommend. NTAG216 only earns its higher price if you're stacking multiple NDEF records on one tag. You'll also see NTAG215 a lot in inventory and asset-tracking setups, where that extra headroom leaves space for an asset ID plus a short note.

Confirm the chip family: why NTAG21x, not MIFARE

MIFARE Classic, Ultralight, and DESFire are built for a different job: transit passes, access-control badges, multi-application systems. Classic's encryption has been publicly broken. Ultralight has no cryptographic protection at all. DESFire's certified security targets organizations running multi-app deployments — none of that is what you need just to write a URL from your phone. Buy NTAG21x, unless a project specifically requires MIFARE compatibility with existing hardware. Listings mentioning "NFC Forum Type 2" compliance are telling you the tag reads and writes with any standard NFC phone. Planning to pack more than one NDEF record onto a tag? Read custom NDEF records beyond URL and text before you settle on a memory size.

Common problems and fixes

Tags that turn out to be 125 kHz RFID, not NFC

This is the single most common bad purchase. 125 kHz RFID tags run on a completely different frequency than the 13.56 MHz NFC uses, and no phone has an LF reader — so a 125 kHz tag simply won't work with an iPhone or Android device. These tags look identical to real NFC stickers and often turn up in generic "RFID sticker" listings with no chip name or frequency stated anywhere. Check for 13.56 MHz or a named NFC Forum Type 2/4 chip before buying. If neither shows up in the listing, treat that silence as a red flag.

Tags with unknown or locked write state

A locked tag has been write-protected and won't accept your data — a common cause of "won't write" complaints. No-name sellers sometimes ship tags in an unknown lock state simply because they never tested them. There's a security angle here too: an unknown lock state can mean a tag someone else configured still holds leftover data you didn't put there. Buy from a listing that states the tag ships unlocked.

Materials and form factor

PVC cards hold up best for wallets and badges. Adhesive stickers are cheapest and fine for one-time placements — plant pots, shelf labels, that sort of thing. Keyfobs and wearables suit anything handled or worn daily. None of this touches compatibility; it's just physical wear.

Doing this on NFCore specifically

Once you've got a tag in hand, open NFCore and read it before writing anything. The app shows chip type and lock state, so you can confirm you got what the listing promised. On iPhone, Core NFC's background tag reading requires the tag to be NDEF-formatted — that's what gives you the no-app-needed pop-up on a finished tag, though writing always means opening NFCore first. Android's fuller NFC stack handles both without that restriction. From there, NFCore walks you through writing your first NDEF record — on the App Store and Google Play.

Frequently Asked Questions

What's the difference between NTAG213, NTAG215, and NTAG216?

Same chip family, three memory sizes — 144, 504, and 888 bytes. NTAG213 fits a short URL, NTAG215 comfortably fits a URL, vCard, or Wi-Fi record, and NTAG216 is for multiple NDEF records on one tag. If you're unsure, NTAG215 is the safest default.

Do I need a MIFARE tag instead of an NTAG tag?

Almost never, for a personal or small-business project. MIFARE is built for transit passes, access-control cards, and multi-application systems — not for writing your own NDEF records from a phone. Buy NTAG21x unless a project requires MIFARE compatibility with existing hardware.

How do I avoid buying 125 kHz tags by mistake?

Check the listing for the frequency (13.56 MHz, not 125 kHz) or a named chip like NTAG213/215/216. A listing that just says "RFID sticker" with no chip name or frequency is a red flag — it may not work with a phone at all.

Does it matter if a tag is "locked" when I buy it?

Yes. A locked tag is write-protected and won't accept your data. Cheap no-name tags sometimes arrive locked or in an unknown state, a common cause of "won't write" complaints. Buy from a listing that states the tag ships unlocked.

What should I look for in materials and form factor?

PVC cards suit wallets and badges; adhesive stickers are cheapest for one-time placements like plant pots or shelf labels; keyfobs and wearables suit daily handling. None of this affects compatibility — it's purely physical durability.

Conclusion

It comes down to three checks: the right memory size (NTAG215 if you're unsure), the right chip family (NTAG21x, not MIFARE, for almost everyone), and confirmation it's genuinely 13.56 MHz NFC, not mismarketed 125 kHz RFID. Get those right and the rest — material, form factor, color — is personal preference. NFCore handles reading, verifying, and writing the tag itself.