Two-way conversion between Flipper Zero .nfc and Chameleon Ultra .json. MIFARE Classic 1K & 4K. Writes only the blocks belonging to the card type — no leftover buffer is carried over.
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Drop your .nfc file here
or click to choose · converted locally, nothing leaves your machine
Sector trailers are shown in amber, flagged blocks in red (non-empty blocks beyond the card type's limit — typically leftovers from a previous slot buffer). The conversion drops them automatically, so the output is always consistent.