Apex NFC Share is only 254 bytes

Got a weird issue with my Apex flex. When trying to add the ‘NFC Sharing’ applet I only get 254 bytes, no matter which storage size I select (tired 1,2,4 and 8kB). I can read/write data on the 254 byte applet just fine, but that’s all the space it seems to allow.

Plenty of free memory on the Apex itself (84336 bytes free).

Wonder if this has happened to anyone else and what I can do about taking advantage of the extra NDEF storage space (hopefully without needing to reformat and re-input all my OTPs!)

This maybe sucking eggs, but just to make sure we are are singing on the same song sheet…

What are you using to view how much space it is using? Apex Manager?

Have you tried Destroying your NDEF / NFC Share via the Fidesmo App

Have you confirmed it was destroyed before trying to add a new one?
Should show as success

Then added a new one, and confirmed it was also successful

:rofl: :rofl: :rofl:

SO, Trying to help you through yours, I deleted my 1k changed it to 2k

So to answer your question


Let me see if I can work this out for US…


Thanks for the report. I will investigate.


I’ve tried a bunch of stuff also, and no luck for me.
regardless of the NDEF partition size, it results in a 254kb

I can write records smaller than 254

anything larger and

giphy (1) (3)

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:joy: at least it’s not just me!!!

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Instead of fixing the old NDEF applet and its installation process we used up until now (GitHub - OpenJavaCard/openjavacard-ndef: NDEF tag implementation for JavaCard), we will switch over to the all-new NDEF applet made by Vivokey (i.e. me). This new applet was developed from the ground up, comes with a few nice features and a lot less technical debt. Once the applet is available via Fidesmo (they are currently migrating it), I will write an announcement post on how to use the new applet and its fancy new features.

I can however already offer a sneak peek: Vivokey now has servers registered with Fidesmo acting as Service Providers, giving us much more control over the installation process and UI:

Edit: The new NFC sharing app is live, see New NFC Sharing Applet .



Thanks @StarGate01

FYI @theradioguy


Just tested and it works! I now have a 2KB NDEF partition, thanks for rolling this out!

Side note, the option to load data from a URL is very cool.