Can Android write every kind of tag?
It writes NDEF content to NFC Forum tag types, which covers what almost every deployment needs. Beyond that the limits belong to the tag, the tool and the format rather than to the platform, and Android is the more permissive of the two systems.
What it writes
NDEF content to tags conforming to an NFC Forum tag type: web addresses, text, contacts, Wi-Fi credentials, records naming an application, and the rest of the ordinary repertoire.
It also formats a blank tag, building the structure that marks the memory as ready to hold NDEF content.
And it applies the permanent read only state where the tag supports it, which is a decision rather than a step.
Between them, that covers what a normal deployment needs from start to finish.
Where the limits are
The tag first. A locked tag refuses everything, a password protected one refuses without the key, and a message larger than the free space is rejected rather than truncated.
The tool second. Writing applications differ in which record types they offer, so a type missing from a menu was never attempted.
The chip third. A chip that is not an NFC Forum tag type will not be written as a tag, whatever the platform.
Notice that none of those three is Android. The platform is rarely the binding constraint on writing.
Beyond NDEF
Android exposes the underlying tag technologies as well as the NDEF layer, so software can address a tag directly rather than through records.
That is how configuration, passwords and proprietary layouts are reached, and it is what applications use for chip specific features such as identifier mirroring.
It is also how a tag gets damaged. Writing to a configuration area by accident can set protection with an unknown key or apply lock bits, neither of which is reversible.
Ordinary writing tools stay above that layer, which is why they cannot break a tag in that way.
Compared with iOS
Android is the more permissive platform for writing, both in the range of record types and in access to the layer beneath NDEF.
That makes it the sensible choice as an encoding device when a deployment is produced on one platform and consumed on both.
It does not change what the tags will do afterwards. A tag written on Android and tapped by an iPhone is subject to the iPhone's rules, which are narrower.
So encode on Android if that is convenient, and test the result on both.
Frequently asked questions
Can Android write a tag an iPhone can read?
Yes. The tag is standard, and what differs is which record types each platform acts on afterwards.
Why does my app not offer Wi-Fi records?
Because that tool does not implement them. The limit is the application rather than the platform.
Can Android write to a locked tag?
No. Locking is enforced by the chip, so no platform or application overrides it.
Should I encode on Android rather than iPhone?
It is generally more permissive, which makes it the easier encoding device. Test the result on both platforms regardless.