Erase or format a tag
Hex NFC has two repairs for a tag that will not read, and they do opposite jobs. Erasing writes an empty message over the tag's data area, so readers see a blank tag and the chip stays writable. Formatting writes the Capability Container, the short header a reader looks for before it reads anything else on the tag.
Before you start, scan the tag: on the Hex NFC home screen, tap Scan, then hold the tag against the top of your iPhone. The Tag screen opens once the app has read it. It opens for a tag that is not formatted or whose data will not read as well. A warning on the scan screen is a diagnosis rather than a dead end. On the Tag screen, tap the menu button at the top right, beside Write, then tap Operations…. Both repairs sit under Dangerous Actions at the bottom of the Operations screen, where every operation confirms the tag before it changes it:
A change to a tag's protection holds the tag twice, and so does every operation under Dangerous Actions. The first tap reads the tag's UID and closes straight away, so you can type. The app then asks you to type that UID back, character for character, and the second tap makes the change on the tag you confirmed. Present a different tag on the second tap and the app refuses it rather than changing the wrong one.
Which repair the tag needs
The app names the fault on the screen where you meet it, and the two names take opposite repairs.
Format the tag when the scan screen reads "This tag isn't formatted yet", or the Tag screen reads "Not formatted". The tag has no Capability Container, so nothing you write to it is readable.
Erase the tag when the scan screen reads "This tag's data won't read", or the Tag screen reads "Data won't read". The Capability Container is already in place, so a format has nothing there to repair.
On a tag that still accepts writes, the Tag screen also shows a warning you can tap. It reads "This tag isn't formatted" or "This tag's data won't read". Tapping it opens Operations. A permanently locked tag shows the status but no warning, because both repairs are writes.
Erase a tag
An erase clears the tag's records and leaves the chip writable. It also rebuilds a data area that has stopped reading.
手順 1Open the erase screen
On the Operations screen, tap Erase. The screen that opens says what the erase writes, and warns you before anything reaches the tag.
手順 2Start the erase
Tap Erase tag. Your iPhone asks you for the tag.
手順 3Hold the tag against your iPhone
Rest the top of your iPhone on the tag. The screen reads "Tap 1 of 2. Hold the tag to identify it.", then shows the tag's UID.
手順 4Type the UID back
The screen reads "Type this tag's UID to confirm." and puts the UID beside an empty field. Enter those same characters in the field, with no colons between them and in either case, then tap Erase tag.
手順 5Hold the tag a second time
Hold the tag against the top of your iPhone again. The screen reads "Tag erased." once the app has read the empty message back off the tag.
An erase ends one of two ways. It reports "Tag erased." once the empty message reads back. Otherwise it reports an error naming the fault, with the details under it for a bug report. If a tag does not scan or write covers what to try next.
Format a tag
Use a format on a fresh chip that was not shipped pre-formatted. On NTAG and MIFARE Ultralight tags a format writes the Capability Container only and does not touch the data area. On ISO 15693 tags such as ICODE SLIX2 it also writes an empty message into the first data block. On those tags the message the tag was carrying is gone.
手順 1Open the format screen
On the Operations screen, tap Format.
手順 2Start the format
Tap Format tag. Your iPhone asks you for the tag.
手順 3Hold the tag against your iPhone
Rest the top of your iPhone on the tag. The screen reads "Tap 1 of 2. Hold the tag to identify it.", then shows the tag's UID.
手順 4Type the UID back
The screen reads "Type this tag's UID to confirm." and puts the UID beside an empty field. Enter those same characters in the field, with no colons between them and in either case, then tap Format tag.
手順 5Hold the tag a second time
Hold the tag against the top of your iPhone again. The screen reads "Tag formatted." once the app has read the header back.
On an NTAG or MIFARE Ultralight tag, a format ends in one of three reports:
"Tag formatted." means the header is written, read back and in place, and the tag is ready to take a message.
"Already formatted: nothing written." means the tag was carrying the right header, so nothing reached it. The app sends you to Erase, because a tag that still will not read has its fault in the data area.
"This tag already has a different Capability Container." means the header on the tag does not match the chip the app identified. Nothing was written.
An ISO 15693 tag reports "Tag formatted." every time, because its Capability Container block stays rewritable and the app writes it on every run.
Clear a tag from the record list
A tag can also be cleared from the Tag screen, without going through Operations. A clear write carries no protection change, so it holds the tag once and asks for no typed UID. A write that also arms or removes a password holds the tag twice and asks for the UID. That is the same gate as an operation under Dangerous Actions.
手順 1Delete every record
On the Tag screen, swipe a record left and tap Delete, until the screen reads "No records left". The removals are not on the tag yet.
手順 2Write the empty result
The screen now reads "You've removed every record. Write to clear the tag, or add one back." Below that line, above Add record, tap Write to clear tag. Your iPhone asks you for the tag.
手順 3Hold the tag against your iPhone
Rest the top of your iPhone on the tag and keep it there until the write finishes.