Title: Writing NTAG
Description: Program NTAG and Ultralight cards from saved dumps
URL: /latest/nfc/writing/
Version: latest
Section: NFC
Search index: /search-index.json

# Writing NTAG

> Program NTAG and Ultralight cards from saved dumps

## On this page

- [Prerequisites](#prerequisites)
- [Steps](#steps)
- [Expected result](#expected-result)
- [Troubleshooting](#troubleshooting)
- [FAQ](#faq)

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## Prerequisites
- An NTAG .nfc file on the SD card under /mnt/ghostesp/nfc/.
- NTAG21x or Ultralight tag compatible with the captured image size (NTAG213/215/216 page counts).
- A PN532 or ST25R3916 enabled build with a connected reader module. The Chameleon Ultra cannot write tags.
## Steps
-
Open NFC → Tools → Write. From the NFC menu, open Tools and choose Write.
You should see a list of .nfc files detected on the SD card.
-
Select an image. Tap the file you want to program.
You should see a popup summarizing the tag model, UID (if present), and total pages.
-
Start the write. Choose Write in the popup.
You should see the status change to “Present tag to write…” while GhostESP waits for a blank card.
-
Present the blank tag. Hold the target NTAG on the antenna until the title updates.
You should see “Writing… X%” as each page is written, finishing at “Write complete”.
## Expected result
- Re-scan the card using the [Scanning](/latest/nfc/scanning/) guide to confirm the UID (if applicable) and data match the source image.
- Check the popup for success messages; any failed page write will trigger an error log with the page number.
- Optional: load the card in an external reader to confirm the NDEF payload or application data.
## Troubleshooting
-
File list empty. Ensure .nfc files exist under /mnt/ghostesp/nfc/ and the SD card is mounted.
-
“Present tag to write…” never changes. The PN532 cannot see the card. Re-seat the antenna or try a different blank tag.
-
Write stops mid-way: Remove the tag, power-cycle GhostESP, and retry. Failures often mean the card’s capacity doesn’t match the image.
## FAQ
- Can I clone MIFARE Classic with this flow? No, the Write flow is limited to NTAG/Ultralight dumps today.
- Do I need to keep holding the card after 100%? Hold it until “Write complete” appears; the device finalizes status after the last page.
- Will the UID be overwritten? NTAG UIDs are read-only. The saved UID is used for naming and verification, but the physical card keeps its factory UID.