ST25TN vs NTAG: How STMicroelectronics' Tag Chips Compare

Short answer

The ST25TN is a family of NFC Forum Type 2 tag chips from STMicroelectronics, and it sits in the same slot as NXP's NTAG213. For everyday jobs like a URL, a Wi-Fi record or a vCard, you won't notice a difference when you tap. The differences show up in the datasheet: memory, rated data retention, and a kill feature that permanently disables a tag.

What the ST25TN family is

There are two chips: the ST25TN512 and the ST25TN01K. GoToTags maps them to NXP's lineup: the 512 corresponds to the NTAG203 and NTAG210 class, and the 01K to NTAG212, NTAG213, NTAG215 and NTAG216. Both are Type 2 chips, so the same NDEF reading and writing rules apply that you already use with NTAG stickers.

That mapping is the vendor's positioning, not a guarantee of identical behavior. If you depend on a specific feature, check the datasheet for the exact part.

Memory and retention

NXP lists the NTAG213 at 144 bytes of user memory, 10 years of data retention and 100,000 write cycles.

Tag maker Seritag, in a 2021 announcement, puts the ST25TN01K at 160 bytes and the ST25TN512 at 64 bytes, with a 40-year retention spec. It calls the chips a direct replacement for NTAG213, with the same 7-byte UID and data structure, and says initial tests showed scan distance at least as good as NTAG.

Treat those as vendor figures. Documents count memory differently, so confirm the number for your variant before you plan a layout. If you are unsure how much room a record needs, our guide to what's actually stored on an NFC tag shows the overhead.

In practice, 160 bytes versus 144 is a small gap, and a short URL record fits on either. The 64-byte 512 is different. It suits a bare link and not much else.

The kill feature

This is the clearest difference. GoToTags says ST NFC tags can be permanently deactivated, "rendering it unable to be read or used ever again." Its two example uses are preventing tag hijacking and stopping competitors from learning how tags are used.

Two cautions. First, GoToTags describes the kill feature for ST chips in general and doesn't tie it to the ST25TN by name, so confirm it on the datasheet for the part you buy. Second, killing is the opposite of locking: a locked tag can still be read, while a killed tag is gone for good. NXP's NTAG213 page lists password protection but no kill command.

Where would you use it? Picture a tag on a product that ships to customers, where you want the tag dead once the item is sold or returned. For a plant label or a Wi-Fi sticker, you will probably never want it.

What NTAG gives you that you should check on ST

NTAG213 comes with a few features that many projects lean on:

• A UID ASCII mirror that writes the 7-byte serial into the NDEF message.
• An NFC counter that increments on each read, with an optional counter mirror. We cover both in the NTAG21x counter and ASCII mirror guide.
• An ECC-based originality signature.
• A 32-bit password with an optional cap on failed attempts.

The sources we found for ST25TN don't walk through an equivalent for each of these, so don't assume feature parity. If your project counts taps or authenticates tags, read the ST datasheet for the specific variant first.

Which one should you pick?

Pick NTAG213 if you want the most widely documented chip and your project uses the counter, mirror or signature features. Pick an ST25TN01K tag if you want the longer rated retention or you need a tag you can kill, and your supplier lists the exact chip.

Supply is the other factor. Seritag wrote in 2021 that NTAG213 lead times were approaching a year, which is part of why ST chips appeared in tag catalogs. That was a 2021 shortage, so check current availability rather than relying on it.

Either way, test one tag before you order a batch. Open NFCore (also on Google Play) and read the tag to check the chip details it reports against what the listing promised.

Frequently Asked Questions

Is ST25TN a replacement for NTAG213?

Seritag and GoToTags both position the ST25TN01K as a replacement for NTAG213-class chips, with the same 7-byte UID and data structure. Check the current ST datasheet before relying on a specific feature.

Can I kill an NTAG tag?

NXP's NTAG213 page lists password protection, a counter, a UID mirror and an originality signature, but no kill feature. You can lock memory, which is different from deactivating the tag.

Will my phone read ST25TN tags?

Seritag describes them as working with NFC phones, as Type 2 tags with the same UID and data structure as NTAG. Test one tag with your app before ordering a batch.