Choosing the right NFC Tag can seem a little confusing. If you aren't sure, then talk to us. We've worked on hundreds of projects and have supplied tags to thousands - we are always happy to help.
First, let's make sure we are clear on the chip and the tag. Each NFC tag contains a microchip, an antenna (coil of wire) and something to hold it together.
The chip, such as an NTAG213 or ST25TN01K defines the memory capacity and features (such as scan counter or password protection).
The tag defines the physical shape/format of the tag. For example, a white sticker, clear sticker or disc.
We will split this into two areas - tag format and tag size.
Note that there is one additional factor to consider if you are placing your tags on metal. Normal tags don't work on metal surfaces so you need to choose an 'on-metal' NFC tag which can work on both metal and non-metal surfaces.
Seritag sell a wide range of tags but most customers use one of two main tag formats - stickers and/or disc tags. Within stickers, there are white, clear, pre-printed (we've already printed these so you can quickly and/or easily use them) or custom print (you can have NFC stickers made with your own design). The format, such as white or clear, does not directly affect scan distance.
As a general rule, the larger the tag, the greater the scan distance or ScanStrength. ScanStrength is how close the phone needs to be to get a response from the tag. A larger ScanStrength or scan distance means the user experience is better as they don't have to 'hunt' for the tag or be so accurate with phone placement.
With mobile phones, the maximum scan distance is acheived with a tag around 50-60mm, however tags from 29-38mm will provide a great user experience for almost all use cases. Tags bigger than this are not only expensive but generally mobile phone phones don't have enough power so scan performance is either flat or starts to reduce.
All our tags have been tested with all popular phones. We only stock the best tags and even our smallest tag will scan without problem. Phone performance varies but to give an idea, our smallest Midas tag has an average scan distance of around 2cm. Our 38mm size tag has an average scan distance of around 5cm. However, bear in mind that the vast majority of people do tend to almost or actually physically touch the tags (or the fabric/card/plastic in front of the tag) when scanning, then in reality all the distances are more than enough.
Seritag stock tags with seven of the most reliable and powerful NFC chips on the market - the new ST25TN01K and ST25TN512 chips, the NTAG213, the NTAG210µ (NTAG210 Micro), ICODE SLIX2 and NTAG413/NTAG424. The 413/424 are specialist authentication NFC chips which need advanced encoding and software. The ICODE SLIX2 is only recommended if you need very long term memory storage. Therefore, the majority of use cases will require either the NTAG213 or NTAG210µ.
To summarise, if :
then go for a 22mm NTAG210µ. Otherwise, go for an NTAG213 tag.
There's a lot more information on the technical differences on our NTAG213 or NTAG210µ page.