Question about writing to SIID with NFC Tools

Hi everyone! I just got my first implant last night (green SIID) and am very excited to start writing to it once the swelling goes down a bit. Just wanted to ask a quick question before I started messing with anything.

So by default the chip has the SIID product page URL written to it. When I go to write something new with NFC Tools do I want to clear the record list first to remove the pre loaded URL and then add a new record, or does adding the new record overwrite what is currently on there?

I just want want to make sure I’m writing to the chip correctly and not add multiple data elements so there is no confusion when scanned by a device.

Any clarification would be appreciated.

Thanks in advance!


Whatever was on there will be deleted when you write something new.
It’s really simple with NFC Tools. Not much to do wrong.

But you can actually put multiple urls or whatever, most phones will just use the first tho’.

Oh and welcome!


Thanks so much for the clarification, I guess I’m just worried to screw something up. If I wanted to clear what is on the chip is it safe to use the clear record function to do that?

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I know that feeling, some weeks ago I had the same with my NExT :slight_smile:

I think I know what you mean, but that button just resets the list of things you are about to write.
Afaik you need to have at least 1 record, but if you want a clean chip, I’d add a text record with only a space.
It’s really just selecting some records, clicking write and tapping for 1 to 2 seconds, so because I don’t have a real usecase for it I just add the last funny youtube video I watched, almost daily.
Even if it says there was an error, you can just write again and it will work.

What if you reset ndef erase it?

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I don’t want to try that, the only NFC tag I have is inside of me and erase sounds scary. I might not know very far (?) when I say afaik.

Yeah I was wondering the same thing, I see things like erase and format but am way too scared to try those things, so I’ll just add a record and see what happens.

Also just curious do these chips have a read or write limit before they stop working, I think I read somewhere they should last between 7 or 10 years, does that include a finite amount of read and writes?

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Yeah, you remember correctly, “10 year data retention. Rated for 100k writes per memory block.” in xSIID Chip Specifications @
But that doesn’t mean it’s the maximum, I think it just means you should expect that many writes.
For my cycle of daily writes, that should be more than fine.


Erase tag is fine trust me I use it all the time

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Nothing to be afraid of, think of it more like a “format”

This is correct but a little misleading, but is better than you think.
Every time you use it, ie. read /write, this time renews… there is a post where Amal explains it, I will try and find it for you…

Also worth a read for you.


Found it


Thanks everyone for all the great info, I love having a place where we can talk about things like this, with a bunch of very knowledgeable people.


Shameless plug for discord to.

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Random question for anyone that has a green SIID. How long did it take for swelling to go down to see the color accurately? I just tried to scan mine after 24 hours with the swelling and the light appeared red in color and not very bright. I’m hoping that will change over the next week. I was just concerned the colors got mixed up and a red led was placed in to a green box. Probably just my OCD kicking in.

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@Devilclarke Might be able to help you. He has a green one. :wink:

It is likely that it is pooled blood…:drop_of_blood:
Have you tried lighting it up in a dark room, looking for any hint of green?

Yeah, I did it in a dark room and it just looked red and definitely not as bright as I’ve seen others to look. Hopefully you’re right about the pooled blood, I’d be so sad if it wasn’t the green chip that I was expecting.

This is mine about 30min after implantation:

After about 2 weeks:


Highly unlikely, But If it was a mistake at DT’s end, Their Customer service is second to none, they WILL sort you out.

FYI the order of brightness is the same order as the image below.
Brightest on the Left ( Green ) to less bright on the Right.

Give it some more time to heal before contacting DT

If you need to, use the web page help

image image

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It’s almost certainly due to the swelling. Just give it a few days. Your body can do lifesaving triage (closing the wound hole) in a few hours, but the rest of the healing proccess takes days or weeks. The swelling will go down and It’ll show up Green soon enough.


Can you take a photo and post?

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