How Much Data Fits on an NFC Tag? Capacity by Chip

What it is (one-paragraph answer)

An NFC tag's storage capacity comes down to the chip inside it — not the sticker, card, or wristband holding it. The three you'll run into most often are NTAG213, NTAG215, and NTAG216: 144, 504, and 888 bytes of user memory respectively. That's roughly 130 to 900 characters of usable text or a URL. Enough for a link or a short vCard on the small end. Enough for multiple NDEF records on the large end.

How it actually works

Total memory vs. user memory

A tag's EEPROM is organized into 4-byte pages, and "total memory" is always a bigger number than "user memory" — the part you actually get to write to. NTAG213 has 45 pages (180 bytes total), NTAG215 has 135 pages (540 bytes total), NTAG216 has 231 pages (924 bytes total). A chunk of that gets eaten up by the UID, lock bytes, and the capability container — none of it available for your NDEF data. So when you're planning what to write, the numbers that actually matter are the "user memory" figures: 144, 504, and 888 bytes.

NDEF overhead eats a few more bytes

Even the user-memory figure isn't fully available for your content. Every NDEF message needs a message header, and every record inside it carries its own header too — type-name-format, type length, payload length. For a single short URL, that overhead barely registers: a few bytes at most. Stack multiple records on one tag, though — say a URL plus a text label — and each one adds its own header. The real ceiling on usable text ends up a bit below the raw byte count.

Where you'll see it

The NTAG21x family (most common)

This is the chip family behind most NFC stickers, cards, and PVC tags you'll buy. NTAG213 (144 bytes) is the default choice for a single short URL or vCard. NTAG215 (504 bytes) covers longer text or a couple of records. NTAG216 (888 bytes) is the one to reach for when you want several NDEF records, or a longer block of text, on one tag.

Beyond NTAG21x

Not every tag is an NTAG21x, though. MIFARE Ultralight — common in low-cost, disposable tickets — has only 64 bytes total, and most of that goes to UID and one-time-programmable bytes. Barely enough room for a short URL. MIFARE Classic 1K nets around 752 usable bytes after its sector-trailer overhead, but it needs its own NFC Forum mapping spec just to carry NDEF data at all. Then there's NTAG 424 DNA — built for tap-to-verify authentication rather than storage, it exposes just a 256-byte NDEF file inside 416 bytes total. That's raw capacity traded for on-chip AES-128 encryption and per-tap dynamic signing.

Zoom out and the NFC Forum's five tag types span roughly 1 KB up to tens of kilobytes or more. But nearly everything a hobbyist or small business buys — NTAG21x, MIFARE Ultralight — falls under Type 2. Capacity really is a chip decision, not a category one.

Tips, gotchas, and a quick how-to with NFCore

Match the chip to the job before you buy in bulk. A single URL, Wi-Fi credential, or vCard fits comfortably on an NTAG213. Need multiple NDEF records, a longer message, or a business card with several fields? Reach for an NTAG215 or NTAG216 instead. Don't treat the marketed user-memory number as your exact character limit, either — leave a small buffer for NDEF header overhead, especially with more than one record. And locking a tag doesn't change how much it holds. It only controls whether it can still be written to.

To check a tag you already own, scan it in NFCore. The tag detail screen shows total user memory, how many bytes your current NDEF content is using, and how much is left — no datasheet lookup required. NFCore flags it before you tap to write if your content won't fit. Available on the App Store and Google Play.

Frequently Asked Questions

How many characters can an NFC tag hold?

Roughly the same as its byte capacity minus a few bytes of NDEF header overhead. A 144-byte NTAG213 holds about 130-140 characters of plain text or a short URL, while an 888-byte NTAG216 holds a few paragraphs or several short records.

What's the biggest NFC tag capacity you can buy?

For everyday Type 2 tags, NTAG216 at 888 bytes is the practical ceiling. Type 4 chips like NTAG 424 DNA trade capacity for encryption, and specialty formats can reach into the kilobytes, but consumer stickers and cards almost always top out in the NTAG21x range.

Does a bigger tag capacity mean a better tag?

No — capacity is one spec among several. A password-locked NTAG213 can be more secure than an unlocked NTAG216, and NTAG 424 DNA has less raw storage than an NTAG215 but adds tamper-evident authentication that capacity alone can't provide.

How do I check how much space is left on a tag I already have?

Scan it in NFCore. The tag detail view shows total user memory, bytes used by the current NDEF message, and bytes free, without needing to look up the chip's datasheet.