Which device should encode the batch?
Android for anything beyond a handful, and a dedicated reader beyond a few hundred. The friction per tag is small in isolation and it multiplies by the batch size, which is exactly what turns an afternoon of work into a week of it.
Android for most batches
More permissive on record types, with access to the layer beneath NDEF where configuration and mirroring live.
Lower friction per tag, since a foreground application can claim tags in succession without a system interaction each time.
And a wider choice of tools, including ones built for batch work with logging and counting.
For a production run of a few hundred tags, that combination is the practical answer.
Why an iPhone is slower
Reading and writing on iOS happen inside a system managed session, presented as a sheet. An application can keep it open from one tag to the next, but the session still times out after a period.
So a long run means starting a new session each time one times out, and an application that closes the session after each tag makes the rhythm start, tap, dismiss, repeat. Over five tags that is invisible and over five hundred it is substantial.
Take NFC Tools. On iOS it requires an iPhone 7 or later running iOS 15.6 or later, and the app must be launched manually. Background reading is available from the iPhone XS and XR onwards.
None of that makes an iPhone unsuitable for a small run. It makes it the wrong tool for a batch.
When to use a reader
Beyond a few hundred tags, or where the same run repeats regularly.
A reader on a stand with tags brought to it beats a phone held in a hand, on speed and on operator fatigue.
It also allows a properly logged process: written, verified, counted, with a record produced automatically rather than by hand.
The cost is software, which is the part most often underestimated. A reader with nothing to drive it is an expensive paperweight.
Verify on the other platform
Whichever device wrote the tags, verify a sample on the other platform before the batch leaves.
A tag written successfully can still be inert on a phone that did not write it, because the platforms act on different record types.
That check takes minutes and catches the failure that would otherwise be discovered by half your audience.
Verify the outcome rather than the read: tap it and watch what happens, on both.
Frequently asked questions
Can I encode a large batch with an iPhone?
You can, and the system session makes it slow: it has to be started from the application and times out during a long run, even when it writes tag after tag. Android or a dedicated reader suits a batch better.
Does the encoding device affect the tags?
No. A correctly written tag is identical whatever wrote it, which is why you can encode on one platform and deploy for both.
When is a reader worth it?
Beyond a few hundred tags or where the run repeats. Budget for the software, which is the part usually forgotten.
Do I need to test on both platforms?
Yes, on a sample. A tag can be written successfully and still be inert on the platform that did not write it.