NFC Power Users: A Tour of Templates, Batch Write, and the Tag Inspector

Three tools do the heavy lifting once you're past your first few tags. Templates save a reusable combination of NDEF records. Batch Write applies a saved template to a whole stack of physical tags in one pass. And the Tag Inspector shows you exactly what's stored on a tag — NDEF or not. Each one solves a specific annoyance on its own; put together, they turn NFC from a one-tag-at-a-time hobby into a repeatable workflow. Here's what each does, when to reach for it, and how they chain together.

Quick answer

Rebuilding the same tag content by hand every time? That's a job for a Template. Writing that same content to more than a couple of physical tags? Batch Write. And if a tag's doing something you don't expect — or you just want to confirm what's actually on it before handing it to someone — open the Tag Inspector. This layer is built for makers running repeat projects, small businesses tagging inventory or event materials, and anyone troubleshooting a tag that "isn't working."

Step-by-step: Templates, Batch Write, and the Tag Inspector

Templates — build once, reuse forever

A template is really just a saved NdefMessage — one or more record types (text, a URL, a Wi-Fi payload, a vCard, or a custom NDEF record) bundled as a shape you can reuse. Build it once, save it, and pull it back up instead of re-entering a link and a name every time you write a new business-card tag. Take a "new hire badge" template: a name field paired with an internal onboarding link, same structure every time, just different values on each fresh tag.

Batch Write — one template, many tags

Batch Write takes a saved template and applies it to a stack of physical tags in sequence, without re-entering data for each one. This mirrors how batch NDEF encoding already works elsewhere in the NFC ecosystem: pick a template, tap tag after tag, done. This is where the time savings really show up — tagging inventory or assets at scale, prepping event wristbands, labeling a batch of retail displays. One gotcha worth flagging: tags in the same batch should share a type and memory size, so the template you built fits consistently across all of them.

Tag Inspector — see what's actually on a tag

The Tag Inspector shows a tag's UID, its type and supported technology, memory size, locked-or-writable state, and parsed NDEF content. No NDEF data at all? It falls back to a raw memory-page view instead of coming up empty. It's also the fastest way to check what's actually stored on a tag someone hands you, before you decide whether to trust it or overwrite it.

Common problems and fixes

A template doesn't fit on a tag. The tag's memory is smaller than the record set you built — check the Tag Inspector's memory reading first.

Batch Write skips a tag partway through a stack. Usually a tag type changed mid-batch. Read and write behavior differs by the tag's underlying radio technology: NFC-A, NFC-F, ISO-DEP, and NFC-V don't all behave identically even though the NDEF format on top looks the same, so mixing tag families in one batch can trip this up.

Tag Inspector shows "no NDEF data." Not necessarily a broken tag. That's the expected result for a blank tag or one formatted by a different system, and the raw-memory fallback still confirms the tag is readable.

A locked tag won't take a Batch Write. By design. The Tag Inspector flags the tag as read-only before you try, so you're not left guessing why the write failed.

Doing this on NFCore specifically

In the app, the Templates tab feeds straight into Batch Write, and the Tag Inspector is the "what did I just scan" check you can run any time — before a write, after a write, or on a tag you didn't create yourself. One honest caveat: iOS's Core NFC framework limits some of the raw, low-level tag access that Android's full NFC stack allows, so a handful of Tag Inspector details go deeper on Android. Haven't set up NFCore yet? It's on the App Store and Google Play.

Frequently Asked Questions

What's the difference between a template and a single NDEF record?

A single record is one piece of data — a URL, a line of text, a phone number. A template is a saved combination of records you can reuse without rebuilding it every time.

Can I batch write different tag types in the same pass?

Batch Write applies one template across a stack of tags, but they should share the same underlying type (all NTAG213, say) so the write behaves consistently. Memory limits differ across tag families, so a template sized for a larger tag may not fit a smaller one.

Does the Tag Inspector work on tags that aren't NDEF-formatted?

Yes. When a tag has no NDEF message, the Tag Inspector falls back to reading its raw memory pages directly, so you still see the UID and byte-level contents instead of an empty result.

Will Batch Write or the Tag Inspector overwrite a locked tag?

No. NFCore's write tools respect a locked tag's memory, and the Tag Inspector shows the tag as locked/read-only so you know before you try.

Conclusion

Build once, apply at scale, verify with the inspector — that's the whole workflow. Once a template's saved, Batch Write and the Tag Inspector handle the rest, turning a one-off tag project into something repeatable. Want to go past URL and text records entirely? The custom NDEF records guide is the natural next read.